U.S. patent application number 10/910964 was filed with the patent office on 2005-03-17 for methods for the treatment of male and female sexual dysfunction.
Invention is credited to Bodor, Nicholas S..
Application Number | 20050059645 10/910964 |
Document ID | / |
Family ID | 34119807 |
Filed Date | 2005-03-17 |
United States Patent
Application |
20050059645 |
Kind Code |
A1 |
Bodor, Nicholas S. |
March 17, 2005 |
Methods for the treatment of male and female sexual dysfunction
Abstract
Methods for the treatment of female sexual dysfunction,
including treatment of associated postmenopausal symptoms, are
provided using very low doses of
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estr-
a-1,3,5(10)-trien-3-ol, also known as E.sub.2-CDS, which do not
elevate average steady-state peripheral estradiol levels to above
about 50-60 pg/ml. Also, methods for the treatment of male sexual
dysfunction are provided using very low doses of E.sub.2-CDS which
do not substantially elevate average peripheral estradiol levels to
above average normal peripheral levels in the male mammal.
Inventors: |
Bodor, Nicholas S.;
(Gainesville, FL) |
Correspondence
Address: |
IVAX CORPORATION
4400 Biscayne Boulevard
Miami
FL
33137
US
|
Family ID: |
34119807 |
Appl. No.: |
10/910964 |
Filed: |
August 2, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60491233 |
Jul 31, 2003 |
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60491234 |
Jul 31, 2003 |
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60586506 |
Jul 9, 2004 |
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Current U.S.
Class: |
514/176 |
Current CPC
Class: |
A61P 5/30 20180101; B82Y
5/00 20130101; A61K 9/006 20130101; A61P 15/10 20180101; A61P 15/12
20180101; A61K 47/6951 20170801; A61K 9/0056 20130101 |
Class at
Publication: |
514/176 |
International
Class: |
A61K 031/58 |
Claims
What is claimed is:
1. A method for the treatment of female sexual dysfunction in a
female mammal in need of such treatment, said method comprising
administering to said mammal the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carb-
onyloxy]estra-1,3,5(10)-trien-3-ol, in an amount effective to
diminish symptoms of said dysfunction which does not elevate
average steady-state peripheral estradiol levels to above about
50-60 pg/ml.
2. A method according to claim 1, wherein the amount administered
is equivalent in bioavailability to a dose of about 0.03 mg/kg or
less per day when administered intravenously to ovariectomized
female rats.
3. A method according to claim 1, wherein the amount administered
does not elevate average steady-state peripheral estradiol levels
to above about 40 pg/ml.
4. A method according to claim 3, wherein the amount administered
does not elevate average steady-state peripheral estradiol levels
to above about 20 pg/ml or lower.
5. A method according to claim 1, wherein the amount administered
does not provide average peak peripheral estradiol levels above
about 70-90 pg/ml or lower.
6. A method according to Claim, wherein the female mammal is a
woman.
7. A method according to claim 6, wherein the amount administered
is about 0.01 mg/kg or less per day, and is administered
buccally.
8. A method according to claim 7, wherein the amount administered
is from about 0.5 to about 2.0 mg/day.
9. A method according to claim 6, wherein the amount administered
does not elevate average steady-state peripheral estradiol levels
to above about 40 pg/ml.
10. A method according to claim 9, wherein the amount administered
does not elevate average steady-state peripheral estradiol levels
to above about 20 pg/ml or lower.
11. A method according to claim 6, wherein the amount administered
does not provide average peak peripheral estradiol levels above
about 70-90 pg/ml or lower.
12. A method according to claim 6, wherein the female sexual
dysfunction comprises hypoactive sexual desire type female sexual
dysfunction and/or sexual pain type female sexual dysfunction.
13. A method according to claim 6, wherein the female sexual
dysfunction is accompanied by postmenopausal-type symptoms
including at least one member selected from the group consisting of
vaginal dryness/lack of lubrication, night sweats, hot flushes,
insomnia, depression, nervousness, urinary incontinence,
irritability and anxiety.
14. A method according to claim 1, wherein the compound is
administered as a substantially saturated complex with: a
hydroxyalkyl or carboxyalkyl derivative of .beta.- or
.gamma.-cyclodextrin; carboxymethylethyl-.beta.- or
-.gamma.-cyclodextrin; .beta.-cyclodextrin sulfobutyl ether;
dimethyl-.beta.-cyclodextrin; or randomly methylated
.beta.-cyclodextrin.
15. A method according to claim 14, wherein the compound is
administered as a substantially saturated complex with
hydroxypropyl-.beta.-cyclodextr- in,
hydroxypropyl-.gamma.-cyclodextrin,
hydroxyethyl-.beta.-cyclodextrin,
hydroxyethyl-.gamma.-cyclodextrin,
carboxymethyl-.beta.-cyclodextrin,
carboxymethyl-.gamma.-cyclodextrin,
carboxyethyl-.beta.-cyclodextrin or
carboxyethyl-.gamma.-cyclodextrin.
16. A method according to claim 15, wherein the compound is
administered as a substantially saturated complex with
2-hydroxypropyl-.beta.-cyclodex- trin or
2-hydroxypropyl-.gamma.-cyclodextrin.
17. A method according to claim 14, wherein the complex is
administered in an anhydrous formulation.
18. A method according to claim 17, wherein the anhydrous
formulation is a buccal tablet, buccal wafer or buccal patch.
19. A method for the treatment of postmenopausal symptoms in a
postmenopausal woman in need of same, said method comprising
administering to said woman the compound
17.beta.-[(1-methyl-1,4-dihydro--
3-pyridinyl)carbonyloxy]estra-1,3,5(10)-trien-3-ol, in an amount
effective to diminish said symptoms which does not elevate average
steady-state peripheral estradiol levels to above about 50-60
pg/ml.
20. A method according to claim 19, wherein the amount administered
is about 0.01 mg/kg or less per day, and is administered
buccally.
21. A method according to claim 20, wherein the amount administered
is from about 0.5 to about 2.0 mg/day.
22. A method according to claim 19, wherein the amount administered
does not elevate average steady-state peripheral estradiol levels
to above about 40 pg/ml.
23. A method according to claim 22, wherein the amount administered
does not elevate average steady-state peripheral estradiol levels
to above about 20 pg/ml or lower.
24. A method according to claim 19, wherein the amount administered
does not provide average peak peripheral estradiol levels to above
about 70-90 pg/ml or lower.
25. A method according to claim 19, wherein said postmenopausal
symptoms are associated with female sexual dysfunction.
26. A method according to claim 25, wherein said female sexual
dysfunction is of the hypoactive sexual desire type or of the
sexual pain type, or both.
27. A method according to claim 19, wherein the postmenopausal
symptoms include at least one member selected from the group
consisting of vaginal dryness/lack of lubrication, night sweats,
hot flushes, insomnia, depression, nervousness, urinary
incontinence, irritability and anxiety.
28. A method according to claim 19, wherein the compound is
administered as a substantially saturated complex with: a
hydroxyalkyl or carboxyalkyl derivative of .beta.- or
.gamma.-cyclodextrin; carboxymethylethyl-.beta.- or
.gamma.-cyclodextrin; .beta.-cyclodextrin sulfobutyl ether;
dimethyl-.beta.-cyclodextrin; or randomly methylated
.beta.-cyclodextrin.
29. A method according to claim 28, wherein the compound is
administered as a substantially saturated complex with
hydroxypropyl-.beta.-cyclodextr- in,
hydroxypropyl-.gamma.-cyclodextrin,
hydroxyethyl-.beta.-cyclodextrin,
hydroxyethyl-.gamma.-cyclodextrin,
carboxymethyl-.beta.-cyclodextrin,
carboxyethyl-.beta.-cyclodextrin,
carboxymethyl-.gamma.-cyclodextrin or
carboxyethyl-.gamma.-cyclodextrin.
30. A method according to claim 29, wherein the compound is
administered as a substantially saturated complex with
2-hydroxypropyl-.beta.-cyclodex- trin or
2-hydroxypropyl-.gamma.-cyclodextrin.
31. A method according to claim 28, wherein the complex is
administered in an anhydrous formulation.
32. A method according to claim 31, wherein the anhydrous
formulation is a buccal tablet, buccal wafer or buccal patch.
33. A method for the treatment of male sexual dysfunction in a male
mammal in need of such treatment, said method comprising
administering to said mammal the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonylo-
xy]estra-1,3,5(10)-trien-3-ol, in an amount effective to diminish
symptoms of said dysfunction which does not substantially elevate
average peripheral estradiol levels to above average normal
peripheral estradiol levels in the male mammal.
34. A method according to claim 33, wherein the amount administered
is equivalent in bioavailability to a dose of from about 0.01 to
about 0.001 mg/kg per day when administered intravenously to
castrated male rats.
35. A method according to claim 33, wherein the amount is
administered once a day or once every other day until said symptoms
diminish.
36. A method according to claim 35, wherein treatment is resumed
when symptoms recur.
37. A method according to claim 33, wherein the male mammal is a
man.
38. A method according to claim 37, wherein the amount administered
is from about 0.01 to about 0.5 mg/day, and is administered
bucally.
39. A method according to claim 37, wherein the amount is
administered once a day or once every other day until said symptoms
diminish.
40. A method according to claim 39, wherein the treatment period is
for about 2 to 7 days.
41. A method according to claim 40, wherein treatment is resumed
when symptoms recur.
42. A method according to claim 33, wherein the compound is
administered as a substantially saturated complex with: a
hydroxyalkyl or carboxyalkyl derivative of .beta.- or
.gamma.-cyclodextrin; carboxymethylethyl-.beta.- or
.gamma.-cyclodextrin; .beta.-cyclodextrin sulfobutyl ether;
dimethyl-.beta.-cyclodextrin; or randomly methylated
.beta.-cyclodextrin.
43. A method according to claim 42, wherein the compound is
administered as a substantially saturated complex with
hydroxypropyl-.beta.-cyclodextr- in,
hydroxypropyl-.gamma.-cyclodextrin,
hydroxyethyl-.beta.-cyclodextrin,
hydroxyethyl-.gamma.-cyclodextrin,
carboxymethyl-.beta.-cyclodextrin,
carboxymethyl-.gamma.-cyclodextrin, carboxyethyl-.beta.-cyclodextin
or carboxyethyl-.gamma.-cyclodextrin.
44. A method according to claim 43, wherein the compound is
administered as a substantially saturated complex with
2-hydroxypropyl-.beta.-cyclodex- trin or
2-hydroxypropyl-.gamma.-cyclodextrin.
45. A method according to claim 42, wherein the complex is
administered in an anhydrous formulation.
46. A method according to claim 45, wherein the anhydrous
formulation is a buccal tablet, buccal wafer or buccal patch.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority of U.S. Provisional
Applications No. 60/491,234, filed Jul. 31, 2003, No. 60/491,233,
filed Jul. 31, 2003 and No. 60/586,506, filed Jul. 9, 2004
(Attorney Docket No. IVAX0024-P-USA, entitled "TRANSMUCOSAL DOSAGE
FORMS FOR BRAIN-TARGETED STEROID CHEMICAL DELIVERY SYSTEMS"), each
of which is incorporated by reference herein in its entirety and
relied upon.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to methods for the treatment of female
and male sexual dysfunction using a brain-targeted delivery system
for estradiol, namely
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy-
]estra-1,3,5(10)-trien-3-ol, also known as E.sub.2-CDS.
[0004] 2. Background of the Prior Art
[0005] Masters and Johnson defined sexual dysfunction as "the
persistent impairment of normal or usual patterns of sexual
interest and/or response" (Masters et al., Human Sexual Response,
Boston, Mass.: Little, Brown and Co. 1966). The problem came to
national attention when the results of the National Health and
Societal Life Survey were published in 1999. Interviews with over
3000 American men and women aged 18-59 revealed that 31% of men and
43% of women (about 40 million) experienced some degree of sexual
dysfunction. The scope of the problem was such that it was said to
"warrant recognition as a significant public health concern." See
Laumann et al., "Sexual Dysfunction in the United States:
prevalence and predictors," JAMA 281:537 (1999). Although sexual
dysfunction rarely threatens physical health, it can take a heavy
psychological toll, bringing on depression, anxiety, and
debilitating feelings of inadequacy.
[0006] Sexual dysfunction in men includes, in the main, erectile
dysfunction, male orgasmic disorder, inhibited or hypoactive sexual
desire and priapism. Inhibited or hypoactive sexual desire refers
to a decrease in desire for, or interest in, sexual activity and
can result from a variety of causes, including physical illness,
depression, hormonal abnormality or medications that affect
libido.
[0007] Male sexual behavior is composed of proceptive and
consummatory behaviors. The proceptive behaviors include the
awareness of the presence of a receptive female, the pursuit of
that female and the positioning of the body (mounting) to allow
insertion of the penis into the vagina. This latter behavior,
termed intromission, as well as its prerequisite erection of the
penis and eventual ejaculation, are the consummatory components of
masculine sexual behavior. The accomplishment of ejaculation
requires the entire repertoire of the aforementioned behaviors. It
is dependent upon the close coordination of sensory and motor
components of the nervous system which are coordinated at the
levels of the brain and by spinal reflexes.
[0008] Male sexual behavior is steroid-dependent and in most
mammals testosterone, released by the Leydig cells of the testes,
is the hormone involved in permitting the expression of masculine
behavior. In sexually experienced male rats, castration results in
a gradual diminution and an eventual extinction of masculine sexual
behavior. Replacement of the hormone testosterone completely
prevents the loss of masculine sexual behavior [Malmnas, Acta
Physiologica Scand. (Suppl. 395): 9-46, 1973; Damassa et al.,
Hormones and Behavior 8: 275-286, 1977]. Additionally, if after
castration masculine sexual behavior is allowed to wane prior to
the initiation of testosterone replacement, testosterone
replacement can restore the full expression of the behavior
[Davidson et al., in S. Levine (Ed.) Hormones and Behavior,
Academic Press, New York, 1972, pp. 63-103].
[0009] Several lines of evidence indicate that the proceptive
components of masculine sexual behavior are dependent upon the
aromatization in the brain of testosterone to estradiol. First, it
has now been conclusively demonstrated that the blockade of the
conversion of testosterone to estradiol with aromatase inhibitors
or the blockade of estrogen actions with antiestrogens antagonize
the effects of testosterone on masculine sexual behavior.
Consistent with this notion of testosterone metabolism into
estradiol which activates masculine sexual behavior is the
distribution of the enzyme, aromatase. In mammals, aromatase is
reported to be concentrated in the preoptic area, the hypothalamus,
and the amygdala brain regions known to mediate the effects of
testosterone on masculine sexual behavior. For representative
literature, see: N. J. MacLusky, A. Philip, C. Hurlburt and F.
Naftolin, in Metabolism of Hormonal Steroids in the Neuroendocrine
Structures, Eds. F. Celotti, F. Naftolin and L. Martini, Raven
Press, Vol. 13, 1984, pp. 103-116; B. S. McEwen, Science 211:
1303-1311, 1981; Beyer et al., Hormones and Behavior 7: 353-363,
1976.
[0010] Second, following the systemic administration of
testosterone, estradiol appears as the major androgen metabolite in
regions of the brain known to mediate masculine sexual behavior. In
one study of Rhesus monkeys, [.sup.3H]-testosterone was
administered systemically and sections of the brain were extracted
to determine the steroid metabolites present. In the hypothalamus,
preoptic area and amygdala, 50% or more of the radioactivity was
reported to be estradiol, while in other brain structures, the
radioactivity remained as testosterone. In contrast, in peripheral
tissues such as the seminal vesicles, glans penis and the prostate
gland, dihydrotestosterone was the major metabolite (R. W. Bonsall
et al., Life Sciences 33: 655-663, 1983). In a subsequent study,
which more extensively evaluated testosterone metabolism in brain
regions, only the hypothalamus, preoptic area and amygdala were
found to form estradiol significantly (61, 43 and 64%,
respectively). All other brain areas evaluated contained either no
estradiol or less than 10% of the recovered steroids (R. P. Michael
et al., Endocrinology 118: 1935-1944, 1986). Finally, the amount of
estradiol bound to nuclear receptors in the preoptic
area-hypothalamus is directly related to the level of testosterone
in the serum, suggesting that the source of estradiol bound to its
receptor in this brain region is circulating testosterone (L. C.
Krey et al., Brain Res. 193: 277-283, 1980).
[0011] Third, estradiol stimulates the proceptive components of
masculine sexual behavior. Pfaff(J. Comp. Physiol. Psych. 73:
349-358, 1970) administered estradiol benzoate systemically (10
.mu.g/day) for 9 to 11 days to castrated male rats and observed
that estradiol increased mounting, intromissions and ano-genital
sniffing and reduced mounting latency to levels comparable to that
observed following the administration of testosterone propionate
(200 .mu.g/day). Sodersten (Hormones and Behavior 4: 247-256, 1973)
administered estradiol benzoate (100 .mu.g/day) for 24 to 28 days
to male rats castrated 6 weeks previously and found that mounts and
intromissions were equivalent to those observed following similar
treatment with testosterone propionate (100 .mu.g/day).
Ejaculations were less affected by estradiol benzoate then by
testosterone propionate. Gray et al. (Physiology and Behavior 24:
463-468, 1980) administered Silastic pellets containing estradiol
and evaluated sexual behavior 7 days later. They observed that
estradiol stimulated mounting behavior but was less effective than
testosterone in enhancing intromissions and ejaculations.
[0012] For the most part, estrogens have not been proposed to treat
male sexual dysfunction, primarily because of significant
undesirable side-effects. Estrogens are, however, administered to
men in the treatment of prostatic carcinoma. Unfortunately, some
significant toxic effects occur in the male: estrogen treatment
stimulates gynecomastia, causes testicular regression and feminizes
hair growth patterns in men.
[0013] In contrast to the widespread interest in research and
treatment of male sexual dysfunction (MSD), less attention has been
paid to the sexual problems of women. Few studies have investigated
the psychological and physiological underpinnings of female sexual
dysfunction (FSD) and fewer treatments are available for women than
for men. A major barrier to the development of clinical research
and practice has been the absence of a well defined, broadly
accepted diagnostic framework and classification for female sexual
dysfunction. In 2000, the Sexual Function Health Council of the
American Foundation for Urologic Disease proposed such a
classification system and it has been widely accepted and will be
used herein; see Basson et al., J. Urol. 163:888 (2000).
[0014] The normal female sexual response cycle is now divided into
four stages: desire, excitement, orgasm, and resolution. Female
sexual dysfunction may occur at any one, or more than one, stage of
the female sexual response cycle. Shepherd, J. Amer. Pharm. Assoc.
42(3):479(2002). Consensus classifications and definitions, based
on the stages of normal female sexual response are divided into
four broad categories: sexual desire disorders, sexual arousal
disorders, orgasmic disorders, and sexual pain disorders; of these
four, the most common is hypoactive (inhibited) sexual desire
disorder (HSDD). HSDD is defined as persistent or recurrent
deficiency (or absence) of sexual fantasies, thoughts, and/or
desire for, or receptivity to, sexual activity, which causes
personal distress. Researchers have reported that as many as 55% of
all women presenting with complaints of FSD identity HSDD as the
main reason; Wincze et al., Sexual Dysfunction, New York, N.Y.:
Guilford Press; 1991. HSDD can result from, among other etiologies,
physical illness, hormonal abnormality, or medications that affect
libido.
[0015] Estrogens are among the most ubiquitous and important
hormones in the female organism. Estradiol (E.sub.2) is the most
potent natural estrogen, as it has the highest affinity for
estrogen receptors; Ruggiero and Likis, J. Midiwifery and Women's
Health, 47(3), 103-138 (2002). Many of estradiol's pharmacological
effects are mediated through the CNS. Brain-specific steroid
deprivation causes syndromes such as male or female sexual
dysfunction and menopausal vasomotor symptoms ("hot flushes"); see
Greendale et al., Lancet, 353, 571-580 (1999); Yen, J. Reprod. Med.
18(6), 287-296 (1977). In postmenopausal women, sexual dysfunction
may be closely linked to and include symptoms associated with the
estrogen deprivation of menopause, such as vaginal dryness/lack of
lubrication and consequent pain associated with intercourse, which
can be closely associated in turn with diminished sexual desire.
Other postmenopausal symptoms such as night sweats, hot flushes,
insomnia, depression, nervousness, urinary incontinence,
irritability and anxiety are also likely to be associated with
diminished sexual desire. Returning estrogen levels to
pre-menopausal levels to relieve the symptoms of menopause
mentioned above as well as other menopausal symptoms such as
osteoporosis has been the goal of HRT (hormone replacement
therapy).
[0016] A brain-targeted chemical delivery system (CDS) represents a
rational drug design approach which exploits sequential metabolism,
not only to deliver but also to target drugs to their site of
action. A dihydropyridine pyridinium salt-type redox system has
been previously proposed and applied to a number of drugs,
including estradiol. According to this redox system, a centrally
acting drug [D] is coupled to a quaternary carrier [QC].sup.+
through a reactive functional group (such as a hydroxyl function)
in the drug; the [D-QC].sup.+ which results is then reduced
chemically to the lipoidal dihydro form [D-DHC]. After
administration of [D-DHC] in vivo, it is rapidly distributed
throughout the body, including the brain. The dihydro form [D-DHC]
is then in situ oxidized (by the NAD NADH system) to the ideally
inactive original [D-QC].sup.+ quaternary salt which, because of
its ionic, hydrophilic character, is rapidly eliminated from the
general circulation of the body, while the blood-brain barrier
prevents its elimination from the brain. Enzymatic change of the
[D-QC].sup.+ which is "locked" in the brain effects a sustained
delivery of the drug species [D], followed by its normal
elimination. A properly selected carrier [QC].sup.+ will also be
rapidly eliminated from the brain. Because of the facile
elimination of [D-QC].sup.+ from the general circulation, only
minor amounts of the drug [D] will be released in the brain. The
overall result will be a brain-specific sustained release of the
target drug species. See, for example, Bodor U.S. Pat. Nos.
4,540,564; 4,900,837; 4,983,586; 5,002,935; 5,017,566; and
5,024,998; Bodor et al. U.S. Pat. No. 4,617,298; and Anderson et
al. U.S. Pat. No. 4,863,911. The compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-t-
rien-3-ol, which has the structure 1
[0017] and is also known as E.sub.2-CDS, is a specific CDS devised
for estradiol which is described in these patents. In this case,
the lipophilic 17-dihydrotrigonelline ester of estradiol, i.e.,
E.sub.2-CDS, is enzymatically converted to the hydrophilic
trigonellinate ester (E.sub.2-Q.sup.+), which is specifically
retained in the brain due to the characteristics of the BBB. The
hydrophilic E.sub.2-Q.sup.+ form is thus "locked-in" the brain and
is slowly and sustainedly hydrolyzed by esterases to estradiol
(E.sub.2). Similar E.sub.2-CDS.fwdarw.E.sub.2-Q.su- p.+ conversion
in the rest of the body accelerates peripheral elimination and
improves targeting.
[0018] E.sub.2-CDS has been previously suggested for a number of
uses, including treatment of male sexual dysfunction (Anderson et
al U.S. Pat. No. 4,863,911) and weight control (Bodor et al. U.S.
Pat. No. 4,617,298), as well as brain-specific, steroid deprivation
syndromes (such as hot flushes) and for chronic reduction of
gonadotropin secretion for fertility regulation (contraception) or
treatment of gonadal steroid-dependent diseases, such as
endometriosis and prostatic hypertrophy (noted in column 46 of
Bodor et al. U.S. Pat. No. 4,617,298). These prior investigations
focused on the ability of E.sub.2-CDS to produce extremely
long-acting effects (of the order of 1 month) from a single
selected dose of E.sub.2-CDS. This was considered highly desirable
for dosing purposes, as once-a-month administration was deemed
particularly convenient, especially so in women for purposes of
contraception. Initially high levels of peripheral estrogen were
not a concern, as they were lower than the levels produced by
equimolar conventional estrogen, and LH reduction was comparable to
that obtained with equimolar conventional estrogen. In rats, 3
mg/kg of E.sub.2-CDS was typically used to provide activity for a
period of 1 month. Such an amount is generally 10 times the mg/kg
amount expected to be comparable in humans. Thus, a 0.3 mg/kg
amount was expected to provide comparable results in women.
[0019] For an overview of prior work with E.sub.2-CDS, see Brewster
et al., Rev. Neurosci. 2, 241-285 (1990); also see Brewster et al,
J. Pharm. Sci. 77:981-985 (1988), in which doses of E.sub.2-CDS in
20% (w/v) HPPCD as low as 0.1 mg/kg i.v. gave LH suppression for as
long as 18 days (but not 25 days) in castrated female rats.
[0020] Estes et al, Life Sciences 40, 1327-1334 (1987), described a
series of four studies, two in orchidectomized rats and two
(Experiments 3 and 4) in ovariectomized rats, examining the ability
of E.sub.2-CDS to affect LH levels. Experiment 3 examined the
dose-response of LH inhibition in ovariectomized rats on day 12
post-drug treatment following a single i.v. dose of 0.1, 0.5, 2.0
or 5.0 mg/kg of E.sub.2-CDS; of 0.07, 0.35, 1.38, 3.46 or 10.38
mg/kg estradiol; or of DMSO vehicle (0.5 mg/kg). Blood samples were
collected on day 12 post-treatment. Experiment 4 compared a single
i.v. dose of 0.5 mg/kg E.sub.2-CDS with equimolar estradiol
17-valerate for LH inhibition, and blood samples were collected on
day 12 or 18 post-treatment. Serum LH was decreased by 75% and 91%
compared to vehicle at the 2 or 5 mg/kg dosage, respectively, of
E.sub.2-CDS, in Experiment 3. The dose of 0.5 mg/kg gave
heterogeneous results and therefore was reexamined in Experiment 4.
In Experiment 4, LH was significantly decreased by E.sub.2-CDS
compared to estradiol valerate. No serum estradiol analyses were
done in the female tests. In the castrated male rat, a single i.v.
injection of 3 mg/kg of E.sub.2-CDS showed very high serum
estradiol at early time points of 4 and 8 hours (>1000 pg/ml),
and elevated levels for several days post-treatment, but not at 12,
18 and 24 days post-treatment, while LH levels remained very
significantly reduced at 12, 18 and 24 days post-treatment.
[0021] Anderson et al, Life Sciences 42, 1493-1502 (1988) reported
tests in ovariectomized female rats in which the rats received an
intravenous injection of E.sub.2-CDS at 10, 33, 100 or 333 .mu.g/kg
or the vehicle DMSO, 0.5 ml/kg, every two days for seven injections
(2 weeks) or a single injection only 2 days before sacrifice. The
single dose of E.sub.2-CDS caused dose-dependent reduction in serum
LH (39-52%) at 33 to 333 .mu.g/kg, but no effect at 10 .mu.g/kg.
Multiple injections caused 32-76% reduction in serum LH at 10 to
333 .mu.g/kg. Serum estradiol was reported to be unchanged at
E.sub.2-CDS doses of 10 and 33 .mu.g/kg, increased to 21 pg/ml and
23 pg/ml in the single and multiple dose groups, respectively, at
the 100 .mu.g/kg dose, and to 59 pg/ml and 60 pg/ml for the single
and multiple 333 .mu.g/kg groups, respectively. The authors
concluded that a single dose or multiple doses of E.sub.2-CDS can
reduce serum LH without elevating serum estradiol. However, serum
was not collected until two days after the last injection, which in
the case of multiple doses was sixteen days after the first
injection. Thus, estradiol levels at early time points were not
investigated and the authors' conclusion that serum LH can be
reduced in ovariectomized female rats without elevating serum
estradiol only related to serum estradiol values at two days after
the end of the treatment period.
[0022] Rahimy et al., Maturitas 13, 51-63 (1991) reported on the
effects of E.sub.2-CDS on tail-skin temperature of the rat and its
implications for menopausal hot flush. The study evaluated the
effects of E.sub.2-CDS versus E.sub.2 on the tail-skin temperature
(TST) surge associated with administration of naloxone to
morphine-dependent rats. Ovariectomized rats received single or
multiple i.v. doses of E.sub.2-CDS at 1.0 mg/kg or E.sub.2 (0.5 mg
pellet) weekly for 1 to 3 weeks before temperature recording. A
single 1 mg/kg i.v. injection of E.sub.2-CDS attenuated the
naloxone-induced rise in TST by 25% when tested one week after
injection but that amount was not statistically significant.
Multiple i.v. injections of 1 mg/kg (that is, once weekly for three
weeks) significantly attenuated the naloxone-induced rise in TST
when tested one week after the last injection. Multiple doses of
E.sub.2-CDS significantly elevated plasma estradiol. Plasma LH was
significantly suppressed for single and multiple doses of
E.sub.2-CDS. The authors also determined plasma levels of LH and
E.sub.2 after a single i.v. 1.0 mg/kg dose of E.sub.2-CDS to
ovariectomized rats beginning 0.5 hour after drug treatment (0.5,
1, 2, 4, 8, 12, 24, 48, 96 and 168 hours post-injection). Plasma
E.sub.2 concentrations were increased to 1.9.+-.0.08 ng/ml
(1900.+-.80 pg/ml) 30 minutes after E.sub.2-CDS administration,
then decreased by 50% at 3 hours and more than 91% at 24 hours
post-treatment. The authors noted that the morphine-dependent
naloxone-withdrawal rat model was to their knowledge the only
animal model available to evaluate the effectiveness of E.sub.2-CDS
for treatment of hot flushes, but also questioned whether this
model is actually analogous to menopausal hot flushes since in some
animals (50% or less) the E.sub.2-treatment did not completely
stabilize. If the model were truly consistent with the estrogen
deprivation which results in hot flushes, the performance of
estrogens in the test would have been more consistent.
[0023] Moreover, no animal tests of E.sub.2-CDS relating to female
sexual dysfunction such as inhibited sexual desire have ever been
reported.
[0024] Lower doses were also included as part of toxicity testing
in women, as is required to establish safety. However, it was
expected that dosages would need to be about 0.3 mg/kg in
postmenopausal women to effectively suppress LH and treat
postmenopausal symptoms long term.
[0025] Clinical studies of E.sub.2-CDS are reported in Brewster et
al., Rev. Neurosci. 2, 241-285 (1990). The first human testing was
a rising dose study in menopausal women. Each of 10 subjects
received a single i.v. injection of E.sub.2-CDS dissolved in 20%
(w/v) HP.beta.CD. Blood samples were obtained at 15 minutes and 30
minutes and at 1, 2, 4, 8, 24 and 48 hours after drug
administration, as well as at days 4 and 7 after administration.
Doses of E.sub.2-CDS of 10, 20, 40, 80, 160, 320 and 640 .mu.g and
1.28 mg (0.16, 0.32, 0.71, 1.19, 2.80, 5.87, 7.57, 10.0, 19.8 and
19.7 .mu.g/kg, respectively) were given intravenously and blood
samples were analyzed for LH, FSH and 17.beta.-estradiol (E.sub.2).
Minimal effects on plasma LH were found in the 10-40 .mu.g dose
group, threshold effects in the 80-640 .mu.g dose group and
substantial and sustained decreases in plasma LH in the 1280 .mu.g
dose group. In another study, one post-menopausal human volunteer
receiving a single 1280 .mu.g i.v. dose of E.sub.2-CDS was found to
have LH lowered in a "clinically meaningful" way through 96 hours
after E.sub.2-CDS administration. Initial serum estradiol levels
for E.sub.2-CDS, although much less than those for estradiol itself
(which were too high to calculate with the standard curve), in a
postmenopausal volunteer given a single 1280 .mu.g i.v. dose, were
about 1500 pg/ml, which is nevertheless very high. While treatment
of menopausal symptoms such as hot flushes was the ultimate hope of
clinical trials, as discussed by Brewster et al., no such treatment
was in fact reported. Moreover, there was not even an allusion to
treatment of female sexual dysfunction of the hypoactive sexual
desire type or the sexual pain type; indeed, not even studies of
E.sub.2-CDS in an animal model for these conditions have been
previously described or proposed.
[0026] Recently, the generally accepted notion that treatment of
postmenopausal women with estrogen combined with progestin offered
protection from coronary heart disease as well as improvement in
health-related quality of life has not proved to be correct.
Constant elevated peripheral exposure to estrogens may in fact lead
to a number of pathological conditions, including breast cancer,
coronary heart disease and pulmonary embolism; Beral et al.,
Lancet, 360 (9337), 942-944 (2002). Contrary to earlier
expectations, hormone replacement therapy (HRT) does not lower the
incidence of coronary heart disease; Low et al., Am. J. Med. Sci.,
324(4), 180-184 (2002). The estrogen plus progestin combination of
the Women's Health Initiative trial in postmenopausal women was
stopped prematurely due to an unacceptably increased risk for
invasive breast cancer, stroke and heart attack; Rossouw et al., J.
Am. Med. Assoc. 288, 321-333 (2002).
[0027] It is thus apparent that there is a need for methods for
treating female sexual dysfunction, including symptoms of estrogen
deprivation in postmenopausal women, without elevated peripheral
exposure to estrogens.
[0028] With respect to prior investigations in the male, the
Anderson et al. '911 patent showed that, in castrated male rats, an
amount of E.sub.2-CDS of 3 mg/kg i.v. was typically used to provide
activity for a period of 1 month. This amount stimulated mounting
behavior, increased intromission behavior and reduced both mount
latency and intromission latency. The conclusion was that
E.sub.2-CDS was a potent, long-acting stimulant of the proceptive
components of masculine sexual behavior. The Anderson et al. patent
suggested use of E.sub.2-CDS alone if deficits in peripheral
androgen-responsive tissues were not an issue; in other cases,
administration together with an androgen such as testosterone was
suggested. Such an amount of 3 mg/kg is generally 10 times the
mg/kg amount expected to be comparable in humans. Thus, a 0.3 mg/kg
amount was expected to provide comparable results in men. For an
overview of prior work in the male with E.sub.2-CDS, again see
Brewster et al., Rev. Neurosci. 2, 241-285 (1990).
[0029] Despite the foregoing, it is noted that peripheral estradiol
levels were not measured or reported in the Anderson et al. patent.
However, Simpkins et al., J. Med. Chem. 29, 1809-1812 (1986),
reported that after a single i.v. administration of 3 mg/kg
E.sub.2-CDS to castrated male rats, blood samples taken at 12-24
days after administration showed no significant differences in
serum E.sub.2 among E.sub.2-CDS, an equimolar dose of estradiol and
the DMSO vehicle. Anderson et al., Pharmacology Biochemistry &
Behavior 27, 265-271 (1987) noted that only the mounting aspect of
consummatory behavior was positively affected by 3 mg/kg
E.sub.2-CDS administered as a single tail vein injection in DMSO;
ejaculatory behavior was not restored. That Anderson et al. article
also noted that serum estradiol was not elevated in orchidectomized
rats treated intravenously with 3 mg/kg E.sub.2-CDS over controls 4
to 8 days after treatment and suggested studies combining
E.sub.2-CDS with testosterone and/or dihydrotestosterone were
needed to more fully address psychological impotence coupled with
deficiencies of peripheral androgens. Another report of early work
with E.sub.2-CDS appears in Estes et al., Life Sciences 40,
1327-1334 (1987), and includes more specific data for peripheral
estradiol levels. In a first experiment, male rats were
orchidectomized at 2-3 months of age, and two weeks later 3 mg/kg
of E.sub.2-CDS was administered to them by a single tail vein
injection; blood samples were taken at 0, 4, 8, 24 and 48 hours and
at 4, 8 and 12 days post-treatment. Serum estradiol levels exceeded
1000 pg/ml at 4 and 8 hours post-treatment and were still high at
24 hours (637 pg/ml) and at 2 days (285 pg/ml). In a second
experiment, 12, 18 and 24 days post-drug administration, there was
no significant differences found in serum estradiol among the three
test groups (E.sub.2-CDS, estradiol and DMSO control). Virtually
all of these studies reported significant and prolonged (at least
24 days) suppression of LH. Anderson et al., Endocrine Research, 14
(2 & 3), 131-148 (1988), subsequently reported on the effects
of E.sub.2-CDS on serum estradiol and testosterone in middle-aged
(18 months), intact male rats. In those studies, which were
undertaken to investigate effects on body weight, at a dose of 1
mg/kg i.v. in DMSO, E.sub.2-CDS increased serum estradiol levels
100-fold on day 1, and thereafter decreased; nevertheless, those
levels remained 13 times initial levels at 7 days and nearly five
times initial levels at 14 days. Serum testosterone levels were
decreased by 99% one day after E.sub.2-CDS treatment and remained
suppressed by more than 96% through 14 days post-treatment.
[0030] Richard M. Sharpe recently published on the roles of
estrogen on the male in TEM, Vol. 9, No. 9, 371-377 (1998) and
emphasized that the balance in action between androgens and
estrogens might be of central importance at many estrogen target
sites. As examples of this importance, he cites "clover disease" in
sheep, where phytoestrogens in clover caused death in castrated
rams (with low circulating testosterone) but did not greatly affect
intact rams; developmental abnormalities of the male reproductive
system which can be caused by either an estrogen or an
anti-androgen; and the fact that gynaecomastia in males can be
caused by too little androgen or too much estrogen.
[0031] Even more recently, Adaikan et al., International Journal of
Impotence Research 15, 38-43 (2003), note that "Sexual dysfunction
with impotence and loss of libido is an important accompaniment of
deranged testicular pathways and ageing in males. Diagnostically,
low serum testosterone (T) level correlates with impairment of
penile sensitivity, nocturnal penile tumescence and spontaneous
morning erections in man and reduced cavemosal pressure response in
the animal model. Besides clinical signs, the endocrine profile is
further compounded by a functional excess of oestradiol (E.sub.2)
that offsets the delicate E.sub.2-T balance." Hypogonadism and
exposure to environmental estrogens also are characterized by such
hormonal imbalance. Administration of 0.1 and 0.01 mg of estradiol
by oral gavage daily for 1 week (acute test) and for 12 weeks
(chronic test) to groups of sexually mature male rats was found to
significantly increase serum estradiol and significantly decrease
serum testosterone at the higher dose (acute test) and at both
doses (chronic test). The authors also found a significant
prolongation of mount latency, intromission latency, and
post-ejaculatory mounting latency accompanying a two- to five-fold
increase in serum estradiol and simultaneous reduction of
testosterone. Also at the higher dose, the ICP response to nerve
stimulation was significantly impaired.
[0032] It is apparent from the foregoing that, to have a practical
approach to male sexual dysfunction, particularly in the human
male, it is imperative that high peripheral estradiol levels be
avoided.
[0033] It is thus apparent that there is a need for methods for
treating male sexual dysfunction, without elevated peripheral
exposure to estrogens.
SUMMARY OF THE INVENTION
[0034] In a first aspect of the present invention, there is
provided a method for the treatment of female sexual dysfunction in
a female mammal in need of such treatment, said method comprising
administering to said mammal the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonylo-
xy]estra-1,3,5(10)-trien-3-ol in an amount effective to diminish
symptoms of said dysfunction which does not elevate average
steady-state peripheral estradiol levels to above about 50-60
pg/ml.
[0035] In a second aspect of the present invention, there is
provided a method for the treatment of female sexual dysfunction in
a woman in need of such treatment, said method comprising
administering to said woman the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,-
3,5(10)-trien-3-ol in an amount effective to diminish or alleviate
symptoms of said dysfunction which does not elevate average
steady-state peripheral estradiol levels to above about 50-60
pg/ml.
[0036] In a third aspect, the invention provides a method for the
treatment of postmenopausal symptoms in a postmenopausal woman in
need of same, said method comprising administering to said woman
the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-t-
rien-3-ol in an amount effective to diminish or alleviate said
symptoms which does not elevate average steady-state peripheral
estradiol levels to above about 50-60 pg/ml.
[0037] In particular embodiments, the foregoing aspects of the
invention further comprise repeated daily or every other day dosing
of amounts as small as about 0.01 mg/kg or lower (about 0.5 to
about 2.0 mg per day) in postmenopausal women) via buccal
administration, and/or without elevation of average steady-state
estradiol peripheral levels in such women to above about 40 pg/ml,
even about 20 pg/ml or lower, and/or with average peak estradiol
peripheral levels (which are reached shortly after administration)
in such women not above about 70-90 pg/ml or even lower, and/or
administering the active compound in cyclodextrin, particularly as
a substantially saturated complex with
hydroxypropyl-.beta.-cyclodextrin (to achieve the highest degree of
thermodynamic activity).
[0038] In yet another aspect of the present invention, there is
provided a method for the treatment of male sexual dysfunction in a
male mammal in need of such treatment, said method comprising
administering to said mammal the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonylo-
xy]estra-1,3,5(10)-trien-3-ol in an amount effective to diminish
symptoms of said dysfunction which does not substantially elevate
average peripheral estradiol levels to above average normal
peripheral levels in the male mammal.
[0039] In still a further aspect of the present invention, there is
provided a method for the treatment of male sexual dysfunction in a
man in need of such treatment, said method comprising administering
to said man the compound
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]-
estra-1,3,5(10)-trien-3-ol in an amount effective to diminish or
alleviate symptoms of said dysfunction which does not substantially
elevate average peripheral estradiol levels to above average normal
levels in men.
[0040] In particular embodiments, the foregoing aspects of treating
male sexual dysfunction further comprise repeated daily or every
other day dosing of amounts comparable to 0.01 mg/kg i.v. in the
castrated male rat, for example, amounts of about 0.01 to about 0.5
mg per day buccally to men, for such period of time as required
until symptoms diminish (for example, approximately 2 to 7 days in
men), with resumption of daily or every other day dosing when
symptoms recur, and/or administering the active compound in
cyclodextrin, particularly as a substantially saturated complex
with hydroxypropyl-.beta.-cyclodextrin (to achieve the highest
degree of thermodynamic activity).
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Other details of the invention will be apparent from the
following detailed description and accompanying drawings, in which
the Figures are as follows.
[0042] FIG. 1 is a plot of lordosis quotient (percent responders)
versus time in days for varying doses of estradiol-CDS, i.e.,
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy]estra-1,3,5(10)-t-
rien-3-ol (E.sub.2-CDS), at 0.003 mg/kg (.DELTA.), 0.01 mg/kg
(.diamond-solid.), 0.03 mg/kg (.circle-solid.), and of the control
vehicle, hydroxypropyl-.beta.-cyclodextrin (HP.beta.CD) solution
(.box-solid.), in ovariectomized female rats after daily
intravenous (i.v.) injections for five days, with observations
beginning on day 3 following the first injection.
[0043] FIG. 2 is a plot of lordosis quotient (percent responders)
versus time in days for varying doses of estradiol benzoate, at
0.003 mg/kg (.DELTA.), 0.01 mg/kg (.diamond.) and 0.03 mg/kg
(.largecircle.), and of the control vehicle,
hydroxypropyl-.beta.-cyclodextrin (HP.beta.CD) solution
(.quadrature.), in ovariectomized female rats after daily
intravenous (i.v.) injections for five days, with observations
beginning on day 3 following the first injection.
[0044] FIG. 3 is a group of three (3) plots of lordosis quotient
(percent responders) versus time in days for the same doses as in
FIGS. 1 and 2, but grouped so as to compare the same doses of
E.sub.2-CDS and estradiol benzoate.
[0045] FIG. 4 is a plot of LH levels in ng/ml plasma versus time in
days for varying doses of E.sub.2-CDS at 0.003 mg/kg
(.circle-solid.), 0.01 mg/kg (.tangle-solidup.), 0.03 mg/kg
(.box-solid.), and of the control (.diamond-solid.) in
ovariectomized female rats after daily single i.v. tail injections
for five days, with observations beginning on day 3 following the
first injection.
[0046] FIG. 5 is a plot of LH levels in ng/ml plasma versus time in
days for varying doses of estradiol benzoate at 0.003 mg/kg
(.circle-solid.), 0.01 mg/kg (.tangle-solidup.), 0.03 mg/kg
(.box-solid.), and of the control (.diamond-solid.) in
ovariectomized female rats after daily single i.v. tail injections
for five days, with observations beginning on day 3 following the
first injection.
[0047] FIG. 6 is a bar graph illustrating the effect of varying
doses of estradiol-CDS (E.sub.2-CDS), at 0.03 mg/kg (), 0.3 mg/kg
(), 3.0 mg/kg (.box-solid.), and of the control vehicle,
hydroxypropyl-.beta.-cyclodext- rin (HP.beta.CD) solution
(.quadrature.), on the mounting performance (% responders) in
intact male rats, and in castrated male rats at days 0, 3, 7, 14,
21, 28 and 35, after a single intravenous (i.v.) injection.
[0048] FIG. 7 is a bar graph illustrating the effect of varying
doses E.sub.2-CDS, at 0.03 mg/kg (), 0.3 mg/kg () and 3.0 mg/kg
(.box-solid.) and of the control vehicle, HP.beta.CD
(.quadrature.), on the intromission percentage (% responders) in
intact male rats, and in castrated male rats at days 0, 3, 7, 14,
21, 28 and 35 after a single intravenous (i.v.) injection.
[0049] FIG. 8 is a bar graph and accompanying chart illustrating
the effect of varying doses of E.sub.2-CDS, at 0.03 mg/kg (), 0.3
mg/kg (), and 3.0 mg/kg (.box-solid.) and of the control vehicle
HP.beta.CD (.quadrature.), on the mounting frequency in intact male
rats, and in castrated male rats at days 0, 3, 7, 14, 21, 28 and 35
after a single intravenous (i.v.) injection.
[0050] FIG. 9 is a bar graph and accompanying chart illustrating
the effect of varying doses of E.sub.2-CDS, at 0.03 mg/kg (), 0.3
mg/kg () and 3 mg/kg (.box-solid.), and of the control vehicle
HP.beta.CD (.quadrature.), on the mounting latency, in minutes, in
intact male rats, and in castrated male rats at days 0, 3, 7, 14,
21, 28 and 35 after a single intravenous (i.v.) injection.
[0051] FIG. 10 is a bar graph and accompanying chart illustrating
the effect of varying doses of E.sub.2-CDS, at 0.03 mg/kg (), 0.3
mg/kg () and 3 mg/kg (.box-solid.), and of the control vehicle
HP.beta.CD (.quadrature.), on the intromission frequency in intact
male rats, and in castrated male rats at days 0, 3, 7, 14, 21, 28
and 35 after a single intravenous (i.v.) injection.
[0052] FIG. 11 is a bar graph and accompanying chart illustrating
the effect of varying doses of E.sub.2-CDS, at 0.03 mg/kg (), 0.3
mg/kg () and 3 mg/kg (.box-solid.) and of the control vehicle
HP.beta.CD (.quadrature.), on the intromission latency, in minutes,
in intact male rats, and in castrated male rats at days 0, 3, 7,
14, 21, 28 and 35 after a single intravenous (i.v.) injection.
[0053] FIG. 12 is a plot of LH levels in ng/ml plasma versus time
in days for varying doses of E.sub.2-CDS at 0.03 mg/kg (x), 0.3
mg/kg (.diamond-solid.) and 3 mg/kg (.DELTA.) and of the control
vehicle HP.beta.CD (.circle-solid.) in orchidectomized (castrated)
male rats for a period of 35 days after a single intravenous (i.v.)
injection).
[0054] FIG. 13 is a bar graph illustrating the effect of 0.03 mg/kg
() E.sub.2-CDS administered i.v. once, and 0.01 mg/kg ()
E.sub.2-CDS administered i.v. once daily for 10 days, and the
control vehicle, HP.beta.CD (.quadrature.), on the mounting
performance (% responders) in intact male rats, and in castrated
male rats at days 0, 1, 3, 7, 14 and 21.
[0055] FIG. 14 is a bar graph illustrating the effect of 0.03 mg/kg
() E.sub.2-CDS administered i.v. once, and 0.01 mg/kg ()
E.sub.2-CDS administered i.v. once daily for 10 days, and the
control vehicle, HP.beta.CD (.quadrature.), on the intromission
performance (% responders) in intact male rats, and in castrated
male rats at days 0, 1, 3, 7, 14 and 21.
[0056] FIG. 15 is a bar graph and accompanying chart illustrating
the effect of 0.03 mg/kg () E.sub.2-CDS administered i.v. once, and
0.01 mg/kg () E.sub.2-CDS administered i.v. once daily for 10 days,
and the control vehicle, HP.beta.CD (.quadrature.), on the mounting
frequency (number of mounts), in intact male rats, and in castrated
male rats at days 0, 1, 3, 7, 14 and 21.
[0057] FIG. 16 is a bar graph and accompanying chart illustrating
the effect of 0.03 mg/kg () E.sub.2-CDS administered i.v. once, and
0.01 mg/kg () E.sub.2-CDS administered i.v. once daily for 10 days,
and the control vehicle, HP.beta.CD(.quadrature.), on the mounting
latency, in minutes, in intact male rats, and in castrated male
rats at days 0, 1, 3, 7, 14 and 21.
[0058] FIG. 17 is a bar graph and accompanying chart illustrating
the effect of 0.03 mg/kg () E.sub.2-CDS administered i.v. once, and
0.01 mg/kg () E.sub.2-CDS administered i.v. once daily for 10 days,
and the control vehicle, HP.beta.CD(.quadrature.), on the
intromission latency, in minutes, in intact male rats, and in
castrated male rats at days 0, 1, 3, 7, 14 and 21.
[0059] FIG. 18 is a bar graph and accompanying chart illustrating
the effect of 0.03 mg/kg () E.sub.2-CDS administered i.v. once, and
0.01 mg/kg () E.sub.2-CDS administered i.v. once daily for 10 days,
and the control vehicle, HP.beta.CD (.quadrature.), on the
intromission frequency (number of intromissions) in intact male
rats, and in castrated male rats at days 0, 1, 3, 7, 14 and 21.
[0060] FIG. 19 is a plot of LH levels in ng/ml plasma versus time
in days for a dose of 0.03 mg/kg (x) E.sub.2-CDS administered i.v.
once, a dose of 0.01 mg/kg (.circle-solid.) E.sub.2-CDS
administered i.v. once daily for 10 days and of the control vehicle
HP.beta.CD(.largecircle.) in orchidectomized (castrated) male rats
for a period of 14 days.
DETAILED DESCRIPTION OF THE INVENTION
[0061] Throughout the instant specification and claims, the
following definitions and general statements are applicable.
[0062] The patents, published applications, and scientific
literature referred to herein establish the knowledge of those with
skill in the art and are hereby incorporated by reference in their
entirety to the same extent as if each was specifically and
individually indicated to be incorporated by reference. Any
conflict between any reference cited herein and the specific
teachings of this specification shall be resolved in favor of the
latter. Likewise, any conflict between an art-understood definition
of a word or phrase and a definition of the word or phrase as
specifically taught in this specification shall be resolved in
favor of the latter.
[0063] The term "complex" as used herein means an inclusion
complex, in which a hydrophobic portion of the E.sub.2-CDS molecule
(typically a portion of the steroidal ring system) is inserted into
the hydrophobic cavity of the cyclodextrin molecule. For example,
in the case of E.sub.2-CDS and HP.beta.CD, it is believed that in
the 1:1 complex, the aromatic A ring of the steroid is included. At
higher HP.beta.CD concentrations, a 1:2 complex of
E.sub.2-CDS:HP.beta.CD forms and the second HP.beta.CD molecule may
interact with the dihydronicotinate group in the E.sub.2-CDS
molecule.
[0064] As used herein, whether in a transitional phrase or in the
body of a claim, the terms "comprise(s)" and "comprising" are to be
interpreted as having an open-ended meaning. That is, the terms are
to be interpreted synonymously with the phrases "having at least"
or "including at least". When used in the context of a process, the
term "comprising" means that the process includes at least the
recited steps, but may include additional steps. When used in the
context of a composition, the term "comprising" means that the
composition includes at least the recited features or components,
but may also include additional features or components.
[0065] The terms "consists essentially of" or "consisting
essentially of" have a partially closed meaning, that is, they do
not permit inclusion of steps or features or components which would
substantially change the essential characteristics of a process or
composition; for example, steps or features or components which
would significantly interfere with the methods described herein,
i.e., the methods are limited to the specified features and those
which do not materially affect the basic and novel characteristics
of the invention. The basic and novel features herein are the
provision of methods for treating male and female sexual
dysfunction in which the amount of E.sub.2-CDS administered is
carefully controlled so that it diminishes symptoms in an amount
which does not elevate average steady-state peripheral estradiol
levels to above average normal peripheral levels in the male, or
which does not elevate average steady-state peripheral estradiol
levels to above about 50-60 pg/ml in the female. In particular
embodiments, the methods comprise buccal administration of an
anhydrous formulation of a substantially saturated complex of the
compound 17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbo-
nyloxy]estra-1,3,5(10)-trien-3-ol with a hydroxyalkyl, carboxyalkyl
or carboxymethylethyl derivative of .beta.- or .gamma.-cyclodextrin
comprising from about 0.01 to about 0.5 mg of said compound per day
in men and from about 0.5 to about 2.0 mg of said compound per day
in women.
[0066] The terms "consists of" and "consists" are closed
terminology and allow only for the inclusion of the recited steps
or features or components.
[0067] As used herein, the singular forms "a," "an" and "the"
specifically also encompass the plural forms of the terms to which
they refer, unless the content clearly dictates otherwise.
[0068] The term "about" is used herein to mean approximately, in
the region of, roughly, or around. When the term "about" is used in
conjunction with a numerical range, it modifies that range by
extending the boundaries above and below the numerical values set
forth. In general, the term "about" or "approximately" is used
herein to modify a numerical value above and below the stated value
by a variance of 20%.
[0069] The term "saturated" when used in conjunction with a complex
of E.sub.2-CDS in cyclodextrin means that the complex is saturated
with the E.sub.2-CDS, that is, the complex contains the maximum
amount of the E.sub.2-CDS which can be complexed with a given
amount of cyclodextrin under the conditions of complexation used. A
phase solubility study can be used to provide this information.
Alternatively, a saturated complex may be arrived at empirically by
simply adding the E.sub.2-CDS to an aqueous solution of the
selected cyclodextrin until a precipitate (of uncomplexed
E.sub.2-CDS) forms; ultimately, the precipitate is removed and the
solution lyophilized to provide the dry saturated complex.
[0070] The term "substantially", as in "substantially saturated"
means that from 80% to 100%, preferably from 90% to 100%, of the
complex is in saturated form. In any other context, "substantially"
similarly means within 20% of the exact calculated amount,
preferably within 10% of that amount. Whatever the context, within
5% of the calculated amount is most desirable.
[0071] As used herein, the recitation of a numerical range for a
variable is intended to convey that the invention may be practiced
with the variable equal to any of the values within that range.
Thus, for a variable which is inherently discrete, the variable can
be equal to any integer value of the numerical range, including the
end-points of the range. Similarly, for a variable which is
inherently continuous, the variable can be equal to any real value
of the numerical range, including the end-points of the range. As
an example, a variable which is described as having values between
0 and 2, can be 0, 1 or 2 for variables which are inherently
discrete, and can be 0.0, 0.1, 0.01, 0.001, or any other real value
for variables which are inherently continuous.
[0072] In the specification and claims, the singular forms include
plural referents unless the context clearly dictates otherwise. As
used herein, unless specifically indicated otherwise, the word "or"
is used in the "inclusive" sense of "and/or" and not the
"exclusive" sense of "either/or."
[0073] Technical and scientific terms used herein have the meaning
commonly understood by one of skill in the art to which the present
invention pertains, unless otherwise defined. Reference is made
herein to various methodologies and materials known to those of
skill in the art. Standard reference works setting forth the
general principles of pharmacology include Goodman and Gilman's The
Pharmacological Basis of Therapeutics, 10.sup.th Ed., McGraw Hill
Companies Inc., New York (2001).
[0074] The expression "peripheral estradiol levels" as used herein
refers to serum estradiol levels obtained throughout the treatment
period, using repeated dosing on a once per day or every other day
schedule.
[0075] The expression "steady-state peripheral estradiol levels" as
used herein refers to serum estradiol levels obtained throughout
the treatment period, using repeated dosing on a once per day or
every other day schedule, excluding initial peak levels obtained
within 1-2 hours after the initial dose.
[0076] The meanings of the expressions "male sexual dysfunction",
"female sexual dysfunction" and "postmenopausal symptoms" are
well-known and are explained in the foregoing Background of the
Invention.
[0077] The expression "lordosis" as used herein refers to vertebral
dorsiflexion performed by female quadrupeds in response to adequate
stimuli from a reproductively competent male. The lordosis quotient
is calculated as 100.times.number of lordoses/10 mounts.
[0078] The expressions "mounting" and "intromission" are explained
in the foregoing Background of the Invention.
[0079] The expression "male mammal" is intended to include any male
mammal but especially human beings, domestic and farm animals, zoo
animals and rare or endangered or expensive mammalian species.
[0080] The expression "female mammal" is intended to include any
female mammal but especially human beings, domestic and farm
animals, zoo animals and rare or endangered or expensive mammalian
species.
[0081] The active ingredient in the instant methods and
formulations, E.sub.2-CDS, i.e.
17.beta.-[(1-methyl-1,4-dihydro-3-pyridinyl)carbonyloxy-
]estra-1,3,5(10)-trien-3-ol, is well-known, and methods for its
synthesis and its complexation with cyclodextrin has been described
in numerous patents and non-patent publications, including the
various Bodor, Bodor et al. and Anderson et al. patents referred to
in the foregoing Background of the Invention.
Preparation of Apporximately 3% Complex of E.sub.2-CDS with
HP.beta.CD
[0082] Dissolve 232 g of 2-hydroxypropyl-.beta.-cyclodextrin
(HP.beta.CD) (Cerestar, degree of substitution 4.5) in deionized
465 mL water (ASTM Type I) to form an approximately 33% w/v
solution. Adjust the pH to 8.4-9.6 with sodium carbonate 1%
solution. Degas the solution by passing argon through it. Add
slowly, drop-wise, under stirring and bubbling argon, at
20-25.degree. C., a solution of E.sub.2-CDS (7.5 g) in ethanol (188
mL). Allow time after each addition for the solution to become
clear. The addition takes about 4 hours and it is slower at the
end. A clear solution will result. Evaporate the solution to
dryness in a rotary evaporator (bath temperature 35.degree. C.).
Reconstitute the residue in water, calculated to obtain the initial
concentration of the cyclodextrin solution. Filter the solution
through a 47 mm, 0.45 .mu.m nylon 66 membrane filter, while
covering with argon. Freeze-dry the filtrate, grind the resulting
solid in a blender and pass it through a 60 mesh sieve. The
resulting complex, an off-white amorphous solid (.about.233 g), is
transferred in a jar and analyzed. The complex should contain about
29-32 mg E.sub.2-CDS per gram. E.sub.2-CDS should have a
chromatographic purity of at least 97% by HPLC. The yield of
complexation (based on E.sub.2-CDS) should be 82-96%.
Preparation of Approximately 2.5% Complex of E.sub.2-CDS with
HP.gamma.CD
[0083] Dissolve 45 g of 2-hydroxypropyl-.gamma.-cyclodextrin
(HP.gamma.CD) (Wacker, Cavasol W8 HP) in deionized 135 mL water
(DIUF) to form an approximately 25% w/v solution. Adjust the pH to
8.4-9.6 with sodium carbonate 1% solution. Degas the solution by
passing argon through it. Add slowly, drop-wise, under stirring and
bubbling argon, at 20-25.degree. C., a solution of E.sub.2-CDS (1.5
g) in ethanol (3 mL). Allow time after each addition for the
solution to become clear. The addition takes about 4 hours and it
is slower at the end. A clear solution will result. Evaporate the
solution to dryness in a rotary evaporator (bath temperature
35.degree. C.). Reconstitute the residue in water, calculated to
obtain the initial concentration of the cyclodextrin solution.
Filter the solution through 47 mm, 0.45 .mu.m nylon 66 membrane
filter, while covering with argon. Freeze-dry the filtrate, grind
the resulting solid in a blender and pass it through a 60 mesh
sieve. The resulting complex, an off-white amorphous solid
(.about.42 g), is transferred in a jar and analyzed. The complex
should contain about 20-25 mg E.sub.2-CDS per gram. E.sub.2-CDS
should have a chromatographic purity of at least 97% by HPLC. The
yield of complexation (based on E.sub.2-CDS) should be 82-96%.
Preparation of Complex E.sub.2-CDS with CME.beta.CD
[0084] Method A:
[0085] Dissolve 100 mg of E.sub.2-CDS and 500 mg of
O-carboxymethyl-O-ethyl-.beta.-cyclodextrin (CME.beta.CD) in 10 mL
of ethanol and sonicate the solution for 1 hour. Then remove the
solvent, reconstitute the residue with water, filter and
lyophilize. The complex should contain about 25 mg
E.sub.2-CDS/g.
[0086] Method B:
[0087] Dissolve 2 g of CME.beta.CD in 20 mL of 0.10M pH 9.0 borate
buffer. Adjust the pH with 1N sodium hydroxide solution. Then
dissolve 150 mg of E.sub.2-CDS in 2 mL of ethanol and add the
resultant solution to the cyclodextrin solution. Stir for 3 hours
at 0.degree. C. under argon, remove the solvent in vacuo,
reconstitute the residue with pH 9 borate buffer and
lyophilize.
Manufacture of Buccal Tablets for Clinical Trials
[0088] In accord with the invention, a buccal tablet was designed
for use in clinical trials to deliver E.sub.2-CDS transmucosally
and thus avoid the instability of E.sub.2-CDS in gastrointestinal
fluid, which leads to multiple decomposition productions starting
with water addition and/or oxidation, as well as hepatic first pass
metabolism. Transmucosal absorption is highly effective from the
invention's saturated complex of E.sub.2-CDS in HP.beta.CD (as
prepared, for example, in EXAMPLE 2 above) with minimal additives.
A placebo was also prepared for the clinical trials.
1 FORMULATION E.sub.2-CDS E.sub.2-CDS E.sub.2-CDS Placebo 0.5 mg
1.0 mg 2.0 mg E.sub.2-CDS/ 0.00 16.67 33.33 66.67 HP.beta.CD
complex HP.beta.CD 33.33 0.00 0.00 0.00 (freeze-dried) Sorbitol
62.67 82.33 65.67 32.33 powder NF Magnesium 1.00 1.00 1.00 1.00
stearate NF Opadry Yellow 3.00 0.00 0.00 0.00 31F22300 100.00 mg
100.00 mg 100.00 mg 100.00 mg
[0089] Similar buccal tablets can be prepared containing complexes
of E.sub.2-CDS with other cyclodextrins such as HP.gamma.CD,
CME.beta.CD or other cyclodextrin identified in this
specification.
Investigation of Female Rat Sexual Behavior After Overiectomy
[0090] Rationale
[0091] Castration causes the termination of sexual behavior in
rats, but the sexual activity of castrated female rats can be
reestablished by administration of estradiol.
[0092] In female rats, estradiol acts in the hypothalamus and
preoptic area to regulate the expression of lordosis, an important
component of female reproductive behavior and a characteristic
posture of the female for a sexually active male to allow
copulation. Estradiol acts on multiple molecular targets that may
converge on common biochemical pathways to ensure integration of
sensory and neurochemical cues that regulate lordosis expression.
Thus, lordosis was selected as an indicator of restoration of
female sexual function in ovariectomized female rats and an
appropriate indicator for alleviating symptoms of female sexual
dysfunction.
[0093] Circulating luteinizing hormone (LH) is a biomarker
reflecting the CNS effects of estradiol. Estrogen diminishes the
secretion of luteinizing hormone-releasing hormone (LHRH) and hence
reduces the secretion of LH. Therefore, LH and estradiol levels
were investigated to measure the central and peripheral effects of
E.sub.2-CDS, respectively.
[0094] Experimental Design
[0095] Adult female Sprague Dawley rats (220-250 g) from Charles
River Hungary Ltd., Godollo, Hungary, were used. Animals were kept
in community cages (4 animals/cage) in a climate-controlled room
(23.+-.2.degree. C., 50-60% humidity), with a 14 hour light, 10
hour dark cycle of artificial lighting, using reversed light/dark
cycle. Food and water were available ad libitum.
[0096] After a minimum five-day acclimatization period, animals
were ovariectomized under ether anesthesia, then were left to
recover for 3 weeks before testing (reconvalescence). All animals
were treated in accordance with the guidelines of the European
Communities Council Directive (86/609/EEC) and studies were
permitted by the Institutional Animal Care Commission.
[0097] Estradiol benzoate and progesterone were obtained from Sigma
Chemical Co. Inc., Budapest, Hungary.
2-Hydroxypropyl-.beta.-cyclodextrin was purchased from Cerestar
Inc., Hammond, Ind., U.S. Estradiol benzoate was dissolved in 40
w/v% 2-hydroxypropyl-.beta.-cyclodextrin (HP.beta.CD) solution and
diluted with 27 w/v % HP.beta.CD solution (0.29 mg/kg is equimolar
to that of 0.3 mg/kg E.sub.2-CDS). E.sub.2-CDS as a 3% complex with
HP.beta.CD (E.sub.2-CDS-CD) was dissolved in distilled water and
diluted with 27% HP.beta.CD solution. E.sub.2-CDS-CD was
synthesized by Alchem Laboratories Corporation, Alachua, Fla.,
US.
[0098] Behavioral Testing
[0099] After recovery from surgery, ovariectomized female rats were
divided into four groups and treated once a day for five days
intravenously, via a bolus injection through the tail vein, as
follows: (1) control, 27% HP.beta.CD solution; (2) 0.003 mg/kg
E.sub.2-CDS dissolved in 27% HP.beta.CD solution; (3) 0.01 mg/kg
E.sub.2-CDS dissolved in 27% HP.beta.CD solution; and (4) 0.03
mg/kg E.sub.2-CDS dissolved in 27% HP.beta.CD solution. A minimal
number of ovariectomized (8 to 12) females were used per group.
Intravenous treatments either with E.sub.2-CDS or HP.beta.CD
(controls) were carried out daily for 5 days beginning 2 days prior
to the first day of behavior observations, in a volume of 0.05
ml/100 g body weight.
[0100] The investigation of estradiol benzoate (EB) was performed
in newly randomized previously ovariectomized females after a
resting period of 3 weeks. Animals (7 to 11 per group) were treated
with 0.003, 0.01 and 0.03 mg/kg estradiol benzoate intravenously
once a day for 5 consecutive days similarly to the protocol applied
for E.sub.2-CDS. Estradiol benzoate was dissolved in 40% HP.beta.CD
and diluted with 27% HP.beta.CD solution (0.29 mg/kg stock solution
equimolar to that of E.sub.2-CDS).
[0101] The behavior test was conducted in a plexiglass observation
cage during the dark cycle. During behavioral observations, only a
dim red light was on.
[0102] An experienced and active male rat was placed in the arena 5
minutes prior to the female. Each female was observed for the time
of ten successful mounts per test session or for a maximum of 10
minutes, and the number of lordosis responses was recorded. The
lordosis quotient (LQ) expresses the estrogen effect on sexual
receptivity and was calculated as follows:
LQ=100.times.number of lordoses/10 mounts
[0103] The observation of the sexual behavior of each female was
carried out, in the case of E.sub.2-CDS, every day for 22 days; in
the case of EB, investigations were carried out every day for 10
days. On days 0, 3, 7, 10, 12, 15 and 18, blood samples were taken
to determine levels of LH and estradiol. Citrated blood samples
were taken by retro-orbital sinus puncture under light ether
anesthesia. The samples were stored at 4.degree. C. for one hour,
then centrifuged at 1000 g for 10 minutes. Plasma was separated and
stored at -80.degree. C. until assayed. Plasma LH concentrations
from individual samples were measured by double antibody
radioimmunoassay kits obtained from Amersham Pharmacia Biotech,
Rome, Italy. Plasma estradiol levels were determined by double
antibody I.sup.125 isotope-RIA kits obtained from BioChem Immuno
System. The limit of detection was 15 pg/ml.
[0104] Behavioral changes were analyzed using the Mann-Whitney U
test (Siegel, Nonparametric Statistics for the Behavioral Sciences,
New York; McGraw-Hill Book Company, Inc., 1956). The Fisher exact
test was used for percentage comparisons (Zar, Biostatistical
Analysis, Prentice Hall, Inc., Englewood Cliffs, N.J., 1974). Serum
LH data were analyzed for each time and treatment group by analysis
of variance (ANOVA) followed by Bonferroni posthoc test. Plasma LH
and estradiol concentrations were evaluated by the computerized
standard curve program of Prism software (Version 3.0, Graph Pad,
San Diego, Calif., US).
[0105] Results
[0106] FIGS. 1-5 show the results obtained. In FIG. 1, data are
mean.+-.SE for 8-12 animals per group; *p<0.05, **p<0.01,
***p<0.001 using the Mann-Whitney U test. In FIG. 2, data are
mean.+-.SE for 7-11 animals per group, with *, ** and *** as
defined for FIG. 1. The data presented in FIG. 1 and FIG. 2 are
reorganized in FIG. 3 so as to more readily compare the effect of
the same dose of E.sub.2-CDS and estradiol benzoate (E.sub.2-Benz).
In FIGS. 4 and 5, data are mean.+-.SE for 7-12 animals per group,
*p<0.05, **p<0.01, ***p<0.001 using ANOVA followed by the
Bonferroni posthoc test.
[0107] At the dose of 0.03 mg/kg, the lordosis quotient LQ was
significantly enhanced by both E.sub.2-CDS and estradiol benzoate.
In the case of E.sub.2-CDS, this effect lasted from day 3 to day
18, as shown in FIG. 1. The effect from estradiol benzoate was less
pronounced and lasted only from day 3 to day 8; see FIG. 2. As also
seen in FIG. 2 as well as the first portion of FIG. 3, the LQ value
for estradiol benzoate was about three times lower than that
obtained for E.sub.2-CDS: the maximal values of LQ after
E.sub.2-CDS and estradiol benzoate treatments were 73 and 27.3
respectively.
[0108] At the dose of 0.01 mg/kg, E.sub.2-CDS significantly
enhanced the LQ from day 5 to day 11. The increase, although
thereafter not statistically significant, lasted till day 15. This
dose of estradiol benzoate slightly increased the LQ from day 3 to
day 10 (about 3 times less compared to E.sub.2-CDS), but this
effect was not statistically significant. See FIGS. 1, 2 and the
second portion of FIG. 3.
[0109] At the dose of 0.003 mg/kg, doses of the test compounds
slightly enhanced the lordosis quotient, but these effects were not
statistically significant (estradiol benzoate, days 3-7;
E.sub.2-CDS, days 3-18). See FIGS. 1, 2 and the third portion of
FIG. 3.
[0110] FIG. 4 shows that plasma LH levels were suppressed at all
dosage levels of E.sub.2-CDS tested, i.e. at 0.003, 0.01 and 0.03
mg/kg. Even at the low i.v. dose of 0.03 mg/kg, the plasma LH level
was suppressed in a statistically significant manner for up to 18
days; plasma LH suppression lasted for up to 15 days even for the
very low dose of 0.003 mg/kg. In contrast, as shown in FIG. 5, none
of the tested dosages of estradiol benzoate gave statistically
significant LH suppression.
[0111] The foregoing studies show that E.sub.2-CDS can restore
female sexual function in rats and indicate that symptoms of female
sexual dysfunction can be alleviated through its administration to
females, including women, at doses far lower than previously
thought possible, while maintaining appropriate peripheral levels
of estrogen.
Clinical Studies
[0112] Recently, E.sub.2-CDS has been studied in clinical trials of
postmenopausal women given a single 2.5 mg or 5 mg dose of
E.sub.2-CDS administered buccally. Even more recently, in a Phase I
clinical study of postmenopausal women, two different
administration regimens of a 2.86 mg E.sub.2-CDS buccal delivery
tablet were evaluated for safety and effects on hormone levels. The
subjects were 12 healthy postmenopausal volunteers, divided into
two groups of six. In Group A, women were dosed once daily for 10
days (10 doses); in Group B, women were dosed once every other day
for 13 days (7 doses). In both groups, measurements of serum total
and free estradiol, estrone, LH, FSH, prolactin, SHBG and
testosterone were made at certain intervals throughout the
treatment period and also at 72 hours after the last dose and
levels of urinary estrone and the ratio of 2OHE.sub.1/16OHE.sub.1
on Day 1 and 72 hours after the last dose were determined, too. A
brief evaluation of the results follows:
[0113] Results
[0114] 1. Dissolution
[0115] E.sub.2-CDS was administered in a buccal delivery form (a
buccal tablet) as a saturated complex with
hydroxypropyl-.beta.-cyclodextrin. The median buccal dissolution
time (and "buccal residence time") was 11 minutes and 13 seconds
(minimum 1.12 min.sec, maximum 23.03 min.sec). This dissolution
time is convenient for patients.
[0116] 2. Estradiol (E.sub.2)
[0117] During the first 24 hours after the administration of 2.86
mg E.sub.2-CDS, the maximum concentration (C.sub.max) of E.sub.2 in
serum was 102.+-.20.2 pg/mL (with subject 12, who subsequently
showed much higher levels than all other subjects), and this peak
was reached at 1.2.+-.0.4 hours. The C.sub.max without subject 12
was 97.8.+-.20.0 pg/mL. The average C.sub.max in the earlier
clinical trial, which used a buccal delivery form with an average
45 minute dissolution rate, was 153.4 pg/mL after 2.5 mg
E.sub.2-CDS, with T.sub.max of 2 hours. One explanation for this
difference might be the difference in the dissolution (and buccal
residence) time of the two formulations used in these two different
studies.
[0118] Neither of the administration regimens (once daily, versus
once every other day) resulted in an accumulation, i.e. increase,
in the trough serum estradiol levels (CTR), measured always before
the next consecutive dose of E.sub.2-CDS. However, the serum levels
that were established during the repeated dosing were different
between the two administration regimens. At steady state E.sub.2
CTR.sub.max of 95.3.+-.76.6 pg/mL was reached with the daily
administration (if values for subject 12 are omitted, this
concentration is 65.2.+-.23.2 pg/mL). The steady state CTR.sub.max
serum concentration of E.sub.2 was 26.4.+-.9.8 pg/mL with the every
other day administration regimen.
[0119] The post-study (72 hours after the last dose) E.sub.2
concentration was 11.5.+-.2.7 pg/mL in the every other day group,
and 36.8.+-.54.6 pg/mL in the once daily group, respectively. In
the once daily group, this post-study value would be 12.5.+-.6.5
pg/mL if the values for subject 12 are omitted.
[0120] 3. Estrone (E.sub.1)
[0121] E.sub.1 was measured during the first 24 hours along with
E.sub.2 and at post-study (i.e. 72 hours after the last dose). The
post-study values were 47.5.+-.49.7 pg/mL (without subject 12:
27.8.+-.12.8 pg/mL) and 31.4.+-.9.4 pg/mL in the once daily, and in
the every other day dosing regimen group, respectively. During
repeated administration a similar trough level pattern to E.sub.2
without accumulation can be anticipated for E.sub.1 as well in both
dosing regimen groups, i.e. a steady state at somewhat higher level
for the once daily administration group, than for the once every
other day group.
[0122] 4. LH Suppression
[0123] During the first 24 hours the maximum decrease in LH was
13.8.+-.4.9 and 12.7.+-.6.8 mIU/mL from baseline in Group A and B,
respectively (Group A showed slightly higher baseline values). This
corresponds to a 35-40 % decrease in LH levels from baseline. The
maximum LH depression occurred at 7.3.+-.5.3, and 7.3.+-.2.7 hours
post-dose in Group A and B, respectively. At post-study (72 hours
after the last dose) LH levels were not different any more from
screening/baseline values. Though the 24-hour LH suppression
profile was determined only during the first 24 hour post-dose
period, a similar daily LH suppression pattern can be anticipated
on each dosing day. Blood samples are available for additional
pre-dose LH measurements for days 3-11 in group A (once daily), and
for days 3, 5, 7, 9, 11, 13, in group B (every other day),
respectively.
[0124] 5. FSH Suppression
[0125] A 15 and 16% suppression in FSH levels was observed during
the first 24 hours post-dose in Group A and B, respectively. The
maximum suppression occurred at 13.2.+-.5.7, and 11.8.+-.5.8 hours
post-dose in Group A and B, respectively. In contrast to LH,
post-study FSH levels were still below the screening/baseline
values (by 14-25%). The kinetics of FSH suppression seems to be
different from that of LH suppression: it develops more slowly
after the administration of E.sub.2-CDS, and FSH remains somewhat
suppressed throughout the entire length of the study, even at 72
hours after the last dose. Blood samples for additional pre-dose
hormone level measurements are available for days 3-11, and 3, 5,
7, 9, 11, 13, in group A and B, respectively. The extent of maximum
FSH suppression (12.5%) during the first 24 hour post-dose in the
previous clinical study after 2.5 mg E.sub.2-CDS was similar to the
extent in this study, having in mind the slightly higher dose (2.86
mg) administered in the second study.
[0126] 6. Prolactin
[0127] Mean baseline concentrations of prolactin were higher in
Group A than in Group B. Likewise, there were higher mean
concentrations on day 13 in Group A than on day 16 in Group B. The
increase in prolactin levels compared to baseline was 29.8 and 16%,
in Group A and B, respectively, by the end of the study. The
differences between the two groups were not statistically
significant.
[0128] 7. SHBG (Sex Hormone-Binding Globulin)
[0129] SHBG concentrations in Group A (day 13) and Group B (day
16), respectively, were by 22.2 and 41.2% higher than at baseline
on day 1. Statistical differences between the groups were not
demonstrated.
[0130] 8. Testosterone
[0131] Serum concentrations of testosterone on day 1 decreased both
in Group A and B. Mean AUC.sub.24 were by 31.1 and 23.0% lower than
baseline AUC.sub.24 (=C.sub.0*24), in Group A and B, respectively.
Serum testosterone concentrations on day 1 decreased to 1.3.+-.1.9
and 4.0.+-.3.9 ng/dL from 22.5.+-.21.0 and 24.0.+-.14.0 ng/dL, in
Group A and B, respectively. The time to reach these minimum
testosterone levels on day 1 were 6.5.+-.11.7 and 7.3.+-.11.3 hours
in Group A and B, respectively. 72 hours after the last
administered dose, testosterone levels returned and slightly
exceeded those of baseline values by 14 and 28% in Group A and B,
respectively. However, the differences between the two groups did
not reach statistical significance in any parameter.
[0132] 9. Urinary Estrone (E.sub.1) and 2OHE.sub.1/16OHE.sub.1
(2-hydroxyestrone/16-hydroxyestrone)
[0133] Urine was collected for 24 hours on day 1 in both groups,
and overnight (8 hours) on day 10 (Group A) and on day 13 (Group
B), respectively, to determine the amounts of voided urinary
estrone (E.sub.1), 2OHE.sub.1, 16OHE.sub.1 and the ratios of
2OHE.sub.1 to 16OHE.sub.1. The mean amounts of E.sub.1 and the
ratios E.sub.1/creatinine in the 24-hour urine on day 1 in both
groups were very similar. Mean amounts and ratios of 2OHE.sub.1 to
16OHE.sub.1 in 8-hour urine on day 10 in Group A appeared slightly
higher than in Group B on day 13. Consequently, the differences of
mean amounts (adjusted to an 8-hour urine collection period) and
differences of mean ratios of day 10-1 in Group A were higher than
the corresponding differences of day 13-1 in Group B (0.15 vs.
0.05). The difference of ratios approached statistical significance
(p=0.077). On the last dosing day (day 10 in Group A, day 13 in
Group B, respectively) mean amounts of 2OHE.sub.1 were 4.46-times
and 2.34-times higher than those values (adjusted to an 8-hour
urine collection period) on day 1 in Group A and B, respectively.
However, the increases in the amounts of urinary 16OHE.sub.1 were
only 2.48, and 1.26-times higher in Group A and B, respectively at
the end of the treatment period compared to the day 18-hour
adjusted values. During treatment the ratios of 2OHE.sub.1 to
16OHE.sub.1 increased by 63.6 and 54.7% in Group A and B,
respectively.
[0134] 10. Safety and Tolerance
[0135] There were seven adverse events (AEs) in total experienced
by four subjects. The AEs were increased SGOT and CPK levels (1-1
case) headaches (2 cases) and 1-1 cases of glossitis, nausea and
vomiting. All AEs were mild or moderate, no serious AE was
observed. The relationship to trial drug was judged to be
reasonably attributable in the single case of glossitis. All other
AEs were considered as not reasonably attributable to the trial
drug. The abnormal laboratory findings were a consequence of
accidental injury and values returned to normal after 7 days. One
AE (headache) required treatment with a single dose of 500 mg
paracetamol. All AEs resolved without sequelae.
[0136] Conslusions:
[0137] The aim of this clinical study was to collect PK data on
serum hormone levels (focus on serum E.sub.2 concentrations) during
a repeated administration study. 2.86 mg E.sub.2-CDS was
administered buccally once daily (group A), or once in every other
day (group B). After reaching a steady state concentration
(65.2.+-.23.2 pg/mL without subject 12 in Group A and 26.4.+-.9.8
pg/mL in Group B, respectively), trough E.sub.2 levels did not
increase with time, there were no signs of accumulation in either
of the two groups. Based on a repeated measure ANOVA of E.sub.2
trough concentrations that did not show a significant effect of
time, or a subject*time interaction between days 7-11 in Group A,
and including days 5, 7, 9, 11, and 13 in Group B, it can be
concluded that the steady state E.sub.2 trough concentrations were
attained by day 5 and 7 in Group B and A, respectively. The
attained steady state peripheral E.sub.2 concentration in group A
was stabilized in a range (65.2.+-.23.2 pg/mL) where clinical
efficacy, i.e. relief of vasomotor and urogenital symptoms would be
expected. However, bearing in mind that the mechanisms of vasomotor
symptoms are mostly CNS mediated, and also based on the preclinical
observations that E.sub.2 is trickled down from the brain as it is
released from the inactive E.sub.2Q.sup.+ precursor trapped behind
the BBB, clinical efficacy is expected also in group B at lower
peripheral trough E.sub.2 levels. For practical reasons an every
other day dosing regimen might be complicated for patients, however
the once daily administration with lower doses (0.5, 0.75, 1.0,
1.25, 1.5, 1.75, 2.0 mg) should be sufficient to ameliorate
postmenopausal symptoms, especially vasomotor and urogenital
symptoms, and to effectively treat female sexual dysfunction,
especially that involving deficiencies in sexual desire or sexual
pain disorders. Further, a four week pack of tablets analogous to
those typically used for dispensing estrogen/progestin
combinations, e.g. Prempro.RTM., or oral contraceptives, could be
used in either case, with the alternate day regimen simplified for
patients by alternating E.sub.2-CDS buccal tablets with placebo
tablets. The occurrence of few adverse events among which only one
was judged as reasonably attributable to the trial drug proves the
excellent safety and tolerance of E.sub.2-CDS when buccally
administered at a low dose. The finding of an increase in the
urinary 2OHE.sub.1 to 16OHE.sub.1 ratio indicates a good safety
profile in terms of breast cancer risk as well. Data from
literature has consistently proven that a lower urinary
2OHE.sub.1/16OHE.sub.1 ratio represents an important biomarker for
increased breast cancer risk. Treatment with E.sub.2-CDS does not
change the metabolism of E.sub.2 and E.sub.1 in a way that would
confer an increased risk for breast cancer, but on the contrary
changes the ratio in a beneficial direction. The metabolite profile
is protective rather than harmful. Because these metabolites
compete for the same estrogenic receptor, the increased amount of
the "good metabolite" (2OHE.sub.1) decreases the possibility that
the "bad metabolite" (16OHE.sub.1) will occupy the estrogen
receptor and initiate cellular events that can lead to mutations
within breast epithelial cells.
[0138] A Phase II clinical trial (first efficacy study or
proof-of-concept study) is under preparation. This new clinical
study is designed to evaluate primarily the effects of E.sub.2-CDS
complexed with HP.beta.CD and delivered by the buccal route
(Estredox.TM.), administered once daily (QD) at three dose levels
(0.5 mg/day, 1.0 mg/day, and 2.0 mg/day), compared to placebo,
during a 12-week treatment phase, on the number and severity of hot
flashes as measured by the "hot flash daily weighted severity
score" (DWSS) in patients suffering from moderate to severe
postmenopausal vasomotor symptoms. Secondary parameters to be
evaluated are the placebo-controlled treatment effects on scores
calculated from a Menopause Rating Scale (MRS) questionnaire in
this patient population. Treatment compliance, and acceptability of
the buccal formulation tablet will also be evaluated among the
secondary parameters of the study. Disintegration time of the
buccal tablets will be recorded on Day 1, 28, and 26. Safety
indices before and after treatment will be evaluated too, and
include physical examination with vital signs, routine safety
laboratory tests, including hemostasis parameters, observed or
reported adverse events, hormone levels as biomarkers of central
estradiol effects, such as serum FSH, LH, prolactin, SHBG, E.sub.2,
E.sub.1, urinary E.sub.1 and the ratio of urinary 2OHE.sub.1 and
16OHE.sub.1, endometrial thickness evaluated by TVS, Pap smear,
vaginal cytology (maturation index) and pH, endometrial aspirate
with Pipelle, and breast examination.
[0139] The primary objective of this study is the evaluation of the
effect of QD Estredox.TM. buccal tablet at doses of 0.5, 1.0, and
2.0 mg E.sub.2-CDS/day compared to placebo on the number and
severity of hot flashes in ambulatory postmenopausal women
suffering from moderate to severe vasomotor symptoms (hot flashes)
during 12 weeks of treatment.
[0140] Secondary objectives include the evaluation of
placebo-controlled effects of three doses of Estredox.TM. (0.5,
1.0, and 2.0 mg E.sub.2-CDS/day) on the scores of the MRS
questionnaire obtained before, during (at weeks 4 and 8) and after
12 weeks of treatment. Treatment compliance and the acceptability
of the buccal tablet are also to be determined and tablet
disintegration times are to be recorded on three occasions (Day 1,
28, and 56).
[0141] The safety of Estredox.TM. treatment is to be determined by
measuring vital signs, routine laboratory, including hemostasis
parameters, and biomarkers to confirm central estrogenic effects,
such as serum FSH, LH, E.sub.2 together with prolactin, SHBG, and
E.sub.1, urinary E.sub.1 and the ratio of urinary
2OHE.sub.1/16OHE.sub.1 before, during (except prolactin, SHBG, and
urine--at weeks 4 and 8) and after the 12 weeks treatment period.
Patients are to also undergo detailed gynecological examinations
including endometrial thickness by TVS, Pap smear, vaginal cytology
(maturation index) and pH, endometrial aspirate with Pipelle, and
breast examination (mammography and ultrasound) twice; i.e. before
and after treatment (week 0 and 12).
[0142] This is to be a phase II multi-center, repeated
administration, double-blind, placebo-controlled dose-range study
involving 80 ambulatory postmenopausal female patients randomly
assigned in equal numbers into one of four treatment groups.
Patients with an intact uterus, who are not under current estrogen,
or estrogen-progestogen (ET/EPT), phytoestrogen, or selective
estrogen receptor modulator (SERM) therapy can be enrolled. If they
were under previous ET/EPT, phytoestrogen or SERM therapy, then an
appropriate wash-out period will precede the enrollment of
potential study candidates into the study. They first will enter a
two-week no-treatment run-in phase, during which patients will be
required to keep a diary to record the number and severity of hot
flashes. Only patients experiencing more than 50 moderate to severe
hot flashes per week (>7 per day on average) will be eligible
for enrollment into the treatment phase of the study. Eligible
patients will be allocated randomly and in equal numbers into one
of the four treatment groups. Patients in all treatment groups will
receive once daily (QD) in a double-blind fashion either one
placebo buccal tablet, or one identical Estredox.TM. buccal tablet
at a dose of 0.5, 1.0, or 2.0 mg E.sub.2CDS/day on each morning of
the study, for 84 days, under fasting conditions. The
disintegration times of the buccal tablets will be recorded on Days
1, 28, and 56 when patients will self-administer the tablets at the
site in the presence of study personnel. During the treatment
period, patients will continue the recording of the number and
severity of hot flashes. There will be interim assessments of the
MRS questionnaire scores after 28 and 56 days of treatment (after
weeks 4 and 8) and evaluation of compliance and adverse events. At
these interim visits blood will also be sampled for determination
of certain hemostasis parameters, and for serum hormone
concentrations (E.sub.2, E.sub.1, FSH, LH only). The 12-week
treatment period will fully be evaluated on Day 85 during the
discharge visit.
[0143] Thus, administration of E.sub.2-CDS in accord with the
present invention can provide effective treatment of female sexual
dysfunction, including effective treatment of postmenopausal
symptoms, at doses far lower than previously expected to be
effective for treating women with E.sub.2-CDS for postmenopausal
symptoms. No specific dosages were ever previously suggested for
treating other aspects of female sexual dysfunction such as sexual
desire disorders or sexual pain disorders; in fact, treatment of
these aspects of female sexual dysfunction has not been previously
proposed and no relevant animal testing has been described in the
E.sub.2-CDS literature. Moreover, the E.sub.2-CDS literature
emphasizes the substantial and prolonged suppression of LH levels.
However, while LH inhibition may be more important for certain uses
of estrogens such as contraception, there does not appear to be a
direct connection between LH suppression and treatment of sexual
dysfunction. The low levels of E.sub.2-CDS which can be effectively
administered to women for the treatment of various aspects of
sexual dysfunction in accord with this invention are particularly
surprising; the 0.5 to 2.0 mg daily buccal dose, assuming
approximately 30% bioavailability, calculates to an actual useable
dose of only 0.15 to 0.6 mg per day, which divided by an average
60-70 kg weight, gives an approximate 0.0025 to 0.01 or less mg/kg
dose in women. This is far less than the dose previously expected
to be needed to effectively suppress LH and treat postmenopausal
symptoms for an extended period. Obviously, dosage amounts will
vary with the route of administration and the bioavailability
applicable to the selected route. The particular conditions to be
relieved by administration in accord with the present invention
include female sexual dysfunction, especially of the hypoactive
sexual desire disorder type or of the sexual pain disorder type, as
well as the symptoms linked to those disorders in postmenopausal
women, whether the symptoms are associated with age or with other
causes of estrogen deprivation (such as surgery). These include
vaginal dryness/lack of lubrication and consequent pain associated
with intercourse, vasomotor symptoms such as night sweats and hot
flushes, insomnia, depression, nervousness, urinary incontinence,
irritability and anxiety, even fear of pain of intercourse, all of
which may be associated with the hypoactive sexual desire disorder.
Of course, other conditions associated with the estrogen
deprivation of menopause or postmenopause, such as osteoporosis and
Alzheimer's disease, are also expected to be diminished by
administration of the low-dose E.sub.2-CDS formulations provided
herein. And these dosages do not provide constant elevated
peripheral estrogen levels comparable to pre-menopausal levels,
such as produced by standard HRT therapy. Rather, E.sub.2-CDS is
believed to be effective in diminishing the symptoms indicated
above in amounts which do not elevate average steady-state
peripheral estradiol levels to above about 50-60 pg/ml. Indeed, an
effective dosage level may be selected in which such average
peripheral estradiol levels do not exceed 40 pg/ml, or even 20
pg/ml or lower, with average peak estradiol peripheral levels not
above 70-90 pg/ml or even lower. It is important to this invention
to use repeated small doses rather than single large ones to
produce average peripheral estradiol levels which are low enough
(50-60 pg/ml, 40-50 pg/ml, 20 pg/ml or lower, steady-state) and not
above an average of about 70-90 pg/ml peak to minimize estrogen
exposure in women.
Investigation of Male Rat Sexual Behavior After Orchidectomy
[0144] Rationale
[0145] Castration causes the termination of sexual behavior in
rats, but the sexual activity of castrated male rats can be
reestablished by administration of estradiol. This has also been
previously shown for administration of E.sub.2-CDS to castrated
male rats in Anderson et al. U.S. Pat. No. 4,863,911. At a single
intravenous dose of 3 mg/kg in tests described therein, E.sub.2-CDS
was found to improve masculine sexual behavior in rats for 28 days
by increasing the pursuit of the female by the male (i.e.,
decreasing mount and intromission latency) and by increasing
initiation of copulatory behavior (increasing mounts and
intromission). These data suggested that E.sub.2-CDS is a potent,
long-acting stimulant of the proceptive components of masculine
sexual behavior. However, estradiol can interfere with ejaculation
and the Anderson et al. patent and other publications relating to
E.sub.2-CDS do not address the issue of estradiol levels resulting
from E.sub.2-CDS administration as to the impact such levels may
have on the treatment of all aspects of male sexual dysfunction,
including erectile function. Moreover, it is now clear that the
drug as used in males in the E.sub.2-CDS literature produces
unacceptably high estradiol levels in the serum for extended
periods of time.
[0146] Circulating luteinizing hormone (LH) is a biomarker
reflecting the CNS effects of estradiol. Estrogen diminishes the
secretion of luteinizing hormone-releasing hormone (LHRH) and hence
reduces the secretion of LH. Therefore, LH and estradiol levels
were investigated to measure the central and peripheral effects of
E.sub.2-CDS, respectively.
[0147] Experimental Design
[0148] Adult male Sprague Dawley rats (300-400 g) from Charles
River Hungary Ltd., Godollo, Hungary, were used. Animals were kept
in community cages (4 animals/cage) in a climate-controlled room
(23.+-.2.degree. C.), with a 14 hour light, 10 hour dark cycle of
artificial lighting, using reversed light/dark cycle. Female rats
weighing 200-250 g were brought to receptivity by subcutaneous
injection of estradiol (50 .mu.g/animal) 48 hours before testing
and progesterone (0.5 mg/animal) 4 hours prior to the experiments.
These hormones were dissolved in sunflower oil.
[0149] After establishment of basal behaviors as discussed below,
selected animals were orchidectomized via a single midventral
incision and were rehoused.
[0150] After repeated testing of animals recovered from
orchidectomy as discussed below, rats were divided into four groups
and treated intravenously, via a single tail vein injection, with
one of the following: group 1: control (27%
hydroxypropyl-.beta.-cyclodextrin); group 2: 0.03 mg/kg
E.sub.2-CDS; group 3: 0.3 mg/kg E.sub.2-CDS; and group 4: 3 mg/kg
E.sub.2-CDS.
[0151] Mating was observed during the dark cycle in a plexi
observation cage in a room where only a dim red light was on. The
male was placed in the observation cage 5 minutes prior to the
female.
[0152] The following parameters were then measured:
[0153] Mount latency (ML): the time from the introduction of the
female to the initial mount or intromission;
[0154] Intromission latency (IL): the time from introduction of the
female to the first intromission; and
[0155] Ejaculatory latency (EL): the time from the first
intromission to ejaculation.
[0156] Sessions were considered negative if IL exceeded 15 minutes.
EL was only measured to check the result of castration, so as to
select only those animals that showed an ejaculation latency
greater than 15 minutes.
[0157] To establish basal behavior, each male was tested every 5
days until four successive and consistent behavioral patterns were
achieved. This pretesting lasted for about four weeks.
Approximately half of the animals tested were deemed suitable for
orchidectomy.
[0158] Twenty-eight days after healing from orchidectomy, the
animals were tested again (Day 0) and divided into 4 experimental
groups. Only animals displaying ejaculation latencies greater than
15 minutes were included in the study.
[0159] Tests of male sexual behavior were conducted 3, 7, 14, 21,
28, 35 and 42 days after drug administration or until the effect
disappeared, i.e. until no statistically significant difference was
found between groups during two consecutive tests.
[0160] Behavioral patterns and related times were recorded manually
by skilled observers.
[0161] After each testing day, a blood sample was taken from each
animal from the retroorbital sinus under light ether anesthesia to
determine serum LH and estradiol levels using double antibody and
I.sup.125 isotope-RIA kits, respectively.
[0162] Estradiol benzoate and progesterone were obtained from
Richter Pharmaceuticals, Ltd., Budapest, Hungary and from Sigma
Chemical Co. Inc., Budapest, Hungary, respectively.
2-Hydroxypropyl-.beta.-cyclodextri- n was purchased from Cerestar
Inc., Hammond, Ind., US. E.sub.2-CDS as a 3% complex with
HP.beta.CD (E.sub.2-CDS-CD) was dissolved in distilled water and
diluted with 27% HP.beta.CD solution. E.sub.2-CDS-CD was
synthesized by Alchem Laboratories Corporation, Alachua, Fla.,
US.
[0163] Behavioral Testing
[0164] Four weeks following orchidectomy, groups of rats were
treated with one of the following drug doses via tail vein
injection: E.sub.2-CDS 0.03, 0.3, and 3 mg/kg. Blood samples were
collected by orbital sinus puncture under light ether anesthesia.
The samples were stored at 4.degree. C. for one hour and
centrifuged at 1,000 g for 10 minutes. Plasma was separated and
stored at -80.degree. C. until assayed. Plasma LH concentrations
from individual samples were measured by double antibody
radioimmunoassay kits obtained from Amersham Pharmacia Biotech,
Rome, Italy. Plasma estradiol levels were determined by I.sup.125
isotope radioimmunoassay kits obtained from BioChem ImmunoSystems.
Concentrations of LH and estradiol were calculated by a
computerized standard curve program using Prism software (Version
3.0, GraphPad, San Diego, Calif., USA). The limit of detection was
15 pg/ml.
[0165] Behavioral changes were analyzed using the Mann-Whitney U
test (Siegel, Nonparametric Statistics for the Behavioral Sciences,
New York; McGraw-Hill Book Company, Inc., 1956). The Fisher exact
test was used for percentage comparisons (Zar, Biostatistical
Analysis, Prentice Hall, Inc., Englewood Cliffs, N.J., 1974). Serum
LH data were analyzed for each time and treatment group by analysis
of variance (ANOVA) followed by Bonferroni posthoc test. Plasma LH
and estradiol concentrations were evaluated by the computerized
standard curve program of Prism software (Version 3.0, Graph Pad,
San Diego, Calif., US).
[0166] Results
[0167] FIGS. 6-12 show the results obtained. In FIGS. 6-12, data
are mean.+-.SE for 8-12 animals per group; *p<0.05, **p<0.01,
***p<0.001 using the Fisher exact test or the Mann-Whitney U
test, as appropriate (Fisher exact test in FIGS. 6 and 7,
Mann-Whitney U tests in FIGS. 8-11). In FIG. 12, each point
represents the mean.+-.SEM of samples obtained from 8 to 13
rats.
[0168] Orchidectomy was found to be less effective in reducing
mounting response (FIG. 6) than in reducing intromission response
(FIG. 7). E.sub.2-CDS restored mounting performance in 100% of the
animals by day 7 at the dose of 0.3 mg/kg and by day 14 and day 21
at the dose of 3.0 mg/kg. The intromission performance was improved
in a statistically significant manner from day 14 through day 28 at
the dose of 3.0 mg/kg.
[0169] Mount frequency was significantly increased on day 7 at
doses of 0.3 and 3.0 mg/kg and on days 14, 21 and 28 at the dose of
3.0 mg/kg (FIG. 8). Mount latency was sharply reduced from day 7
through day 28 for the doses of 0.3 and 3.0 mg/kg (FIG. 9).
[0170] A statistically significant increase in intromission
frequency and a decrease in intromission latency was observed on
days 14, 21 and 28 at the dose of 3.0 mg/kg (FIGS. 10 and 11).
[0171] Thus, the effect of E.sub.2-CDS on the re-establishment of
the tested indications of copulatory behavior in male rats was
significant at doses of 0.3 and 3.0 mg/kg through day 28. The dose
of 0.03 mg/kg had no statistically significant effect.
[0172] Concentrations of plasma LH in intact rats were 1.1.+-.0.15
ng/ml. Four weeks after bilateral orchidectomy, LH levels increased
to 8.13 ng/ml. At the lowest dose of E.sub.2-CDS tested (0.03 mg/kg
i.v.), plasma LH levels were not reduced. At the dose of 0.3 mg/kg
i.v., the title compound significantly reduced the LH levels on
days 1, 3, and 7. By day 15, there was no significant difference in
the LH levels between control and treated animals. At the highest
dose of E.sub.2-CDS tested (3 mg/kg i.v.), LH levels were
suppressed significantly throughout 28 days (FIG. 12).
[0173] Estradiol levels were below the limit of detection in
animals treated with E.sub.2-CDS at doses of 0.03 and 0.3 mg/kg
i.v. At the highest dose tested (3 mg/kg i.v.), the estradiol level
was 258.+-.19 pg/ml on day 1 after treatment. At this dose, the
hormone level decreased by 39% to 165.+-.14 pg/ml on day 3 and to
61.+-.7.7 pg/ml on day 7. When next tested on day 14, the estradiol
level for the highest dose tested was below the limit of detection.
See Table 1 below. This confirms that the dosage level of
E.sub.2-CDS used in the Anderson et al. patent (3 mg/kg single i.v.
dose in rats) would have produced unacceptably high peripheral
estradiol levels for a prolonged period and agrees with data set
forth in the Anderson et al. patent and in the E.sub.2-CDS
literature. This level is expected to be high enough to interfere
with ejaculation.
2TABLE 1 Plasma estradiol concentrations following E.sub.2-CDS or
vehicle treatment in orchidectomized rats. Days relative to Plasma
estradiol Treatment treatments (pg/ml) Vehicle 0 ND** (9/9)* 1 ND**
(9/9)* 3 ND** (9/9)* 7 ND** (9/9)* 14 ND** (9/9)* 21 ND** (9/9)* 28
ND** (9/9)* 35 ND** (9/9)* 0.03 mg/kg E.sub.2-CDS 0 27.3 (9/11)* 1
ND** (10/10)* 3 ND** (10/10)* 7 ND** (10/10)* 14 ND** (10/10)* 21
ND** (10/10)* 28 ND** (10/10)* 35 ND** (10/10)* 0.3 mg/kg
E.sub.2-CDS 0 31.4 (10/12)* 1 ND** (11/11)* 3 ND** (11/11)* 7 ND**
(11/11)* 14 ND** (11/11)* 21 ND** (11/11)* 28 ND** (11/11)* 35 ND**
(11/11)* 3 mg/kg E.sub.2-CDS 0 54 .+-. 21 (8/13)* 1 258 .+-. 19
(0/12)* 3 165 .+-. 14 (0/12)* 7 61 .+-. 7.7 (0/12) 14 ND** (12/12)*
21 ND** (12/12)* 28 ND** (12/12)* 35 ND** (12/12)* *Mean .+-. SEM;
in parentheses: number of samples with estradiol levels below the
detection limit (15 pg/ml) of the assay/number of samples per
group. **ND not detectable
[0174] The testing described above was repeated using a dose of
0.03 mg/kg administered as a single i.v. injection, and a dose of
0.01 mg/kg with daily i.v. administration for 10 days. E.sub.2-CDS
stock solution (40%) was diluted in 27% HP.beta.CD solution.
[0175] The copulatory behavior of E.sub.2-CDS treated groups was
compared to that of the HP.beta.CD control group at 1, 3, 7, 14,
and 21 days after i.v. drug administration in the 0.03 mg/kg group
and at 1, 3, 7, 14 and 21 days after initial i.v. drug
administration in the 0.01 mg/kg.times.10 days group.
[0176] The dose of 0.01 mg/kg administered for 10 days produced
significant effect by day 14. It restored mounting performance in
67% and intromission performance in 50% of animals compared to the
control group (FIGS. 13 and 14). Mount frequency was increased
significantly (FIG. 15). Both mount latency and intromission
latency were reduced significantly (FIGS. 16 and 17 ). Intromission
frequency was not increased significantly (FIG. 18). One animal,
which had good performance before, died on day 7 under the ether
anesthesia.
[0177] The single dose of 0.03 mg/kg improved sexual activity, but
it was not statistically significant in any observations.
[0178] Plasma LH levels were also determined. In the repeated
examination, the plasma LH level was significantly reduced at the
dose of 0.01 mg/kg (10 daily injections) from day 3 to day 14. At
the dose of 0.03 mg/kg (single injection), the plasma LH level was
significantly reduced on day 3 only. The results of the repeated
examination can be seen in FIG. 19.
[0179] At the end of the repeated examination, animals were
over-anesthetized, and the prostate and seminal vesicles were
removed and their weights were measured. The relative prostate and
seminal vesicle weights are summarized in Table 2 below.
3TABLE 2 Relative prostate and seminal vesicle weight of castrated
male rats treated with E.sub.2-CDS Relative seminal Relative.sup.a
prostate weight vesicle weight Treatment Mean .+-. SE Mean .+-. SE
HP.beta.CD i.v. 22.15 .+-. 2.1 25.46 .+-. 1.55 (control)
E.sub.2-CDS 24.78 .+-. 1.6 20.83 .+-. 0.61** 0.01 mg/kg 10x i.v.
E.sub.2-CDS 14.48 .+-. 2.1* 19.18 .+-. 0.82** 0.03 mg/kg 1x i.v.
.sup.amg/100 g body weight; n = 7-12 *p < 0.05, **p < 0.01
Student's t test compared to control
[0180] Estradiol levels were below the limit of detection in all
animals treated with E.sub.2-CDS at doses of 0.03 mg/kg (single
dose) and 0.01 mg/kg (daily for 10 days) i.v. See Table 3
below.
4TABLE 3 Plasma estradiol concentrations following E.sub.2-CDS or
vehicle treatment in orchidectomized rats. Days relative to Plasma
estradiol Treatment treatments (pg/ml) Vehicle 0 ND** (7/7)* 1 ND**
(7/7)* 3 ND** (7/7)* 7 ND** (7/7)* 14 ND** (7/7)* 21 ND** (7/7)*
0.01 mg/kg E.sub.2-CDS 0 ND** (12/12)* daily for 10 days i.v. 1
ND** (12/12)* 3 ND** (12/12)* 7 ND** (12/12)* 14 ND** (12/12)* 21
ND** (12/12)* 0.03 mg/kg E.sub.2-CDS 0 ND** (9/9)* single dose i.v.
1 ND** (9/9)* 3 ND** (9/9)* 7 ND** (9/9)* 14 ND** (9/9)* 21 ND**
(9/9)* *Mean .+-. SEM; in parentheses: number of samples with
estradiol levels below the detection limit (15 pg/ml) of the
assay/number of samples per group. **ND not detectable.
[0181] The foregoing studies show that E.sub.2-CDS can restore male
sexual function in rats and indicate that symptoms of male sexual
dysfunction in males, including men, can be alleviated through it
administration at doses far lower than previously thought possible,
while maintaining appropriate peripheral levels of estrogen.
Clinical studies in women substantiate that low dose buccal
administration of E.sub.2-CDS can be correlated with animal test
data and allow calculation of suitable buccal dosages for men based
on the animal test data in male rats.
[0182] Administration of E.sub.2-CDS in accord with the present
invention provides effective treatment of male sexual dysfunction,
at doses far lower than previously expected to be effective for
treating men with E.sub.2-CDS for male sexual dysfunction by using
repeated small doses of the compound rather than the single dose
once-a-month therapy suggested earlier, to minimize or obviate
elevation of peripheral estradiol levels. It also is not necessary
to use a dosage high enough to significantly reduce serum LH in
order to effectively treat male sexual dysfunction. The low levels
of E.sub.2-CDS which can be effectively administered to men for
these purposes are particularly surprising; for example, a dose
comparable to 0.01 to 0.001 mg/kg i.v. in the male rat, or a 0.01
to 0.5 mg daily buccal dose in men, is contemplated; assuming
approximately 30% bioavailability, this buccal dose calculates to
an actual useable dose of only 0.003 to 0.015 mg per day, which
divided by an average 70-80 kg weight, gives an approximate
0.0000375 to 0.00021 or less mg/kg dose in men. Treatment is
continued once-a-day or once every other day for such period of
time as required until symptoms diminish, generally about 2 to 7
days in men, and treatment is resumed when symptoms recur.
Obviously, dosage amounts will vary with the route of
administration and the bioavailability applicable to the selected
route. In any event, the method of administering E.sub.2-CDS in
accord with the present invention will utilize dosage amounts and
dosage frequencies which will not substantially elevate average
peripheral estradiol levels to above average normal levels in the
male, i.e., will not elevate average peripheral estradiol levels
more than about 10-15% above normal levels. This in turn will
prevent peripheral estradiol levels from inhibiting ejaculation, so
that both proceptive and consummatory aspects of male sexual
behavior will be improved.
[0183] For use herein, E.sub.2-CDS can be administered by a variety
of routes of administration and dosage forms which are already
known from the various Bodor, Bodor et al. and Anderson et al.
patents referenced hereinabove, all of which are incorporated by
reference herein in their entireties and relied upon. This is also
apparent from the dosage forms employed in the animal and human
testing described hereinabove.
[0184] Pharmaceutical formulations for use in the methods of this
invention comprise an amount of E.sub.2-CDS sufficient to diminish
symptoms of female sexual dysfunction, including postmenopausal
symptoms, which does not elevate average steady-state peripheral
estradiol levels above about 50-60 pg/ml, or an amount of
E.sub.2-CDS sufficient to diminish symptoms of male sexual
dysfunction, which does not substantially elevate average
peripheral levels above average normal peripheral levels in the
male mammal. The carrier and any other ingredients must of course
be compatible with E.sub.2-CDS, and not detrimentally affect the
effectiveness of the compound in treating female or male sexual
dysfunction.
[0185] Suitable pharmaceutically acceptable carriers for use with
E.sub.2-CDS are non-toxic and will be apparent to those skilled in
the art of pharmaceutical formulation. See, e.g., Remington's
Pharmaceutical Sciences, 17.sup.th Ed., Gennaro, ed., Mack
Publishing Company, Easton, Pa. (1985). The choice of suitable
carriers will depend upon the exact nature of the particular dosage
form selected, including of course the route of administration. The
therapeutic dosage ranges for administration of E.sub.2-CDS for use
in treating male and female sexual dysfunction has been detailed
hereinabove. The dose selected will of course vary with the
severity of the symptoms treated, the route of administration, the
dosage form and the like. Formulations according to the invention
may be administered in any therapeutically effective manner,
including, but not limited to, bucally, intranasally, sublingually,
orally, topically (dermally), parenterally, by inhalation spray,
vaginally or rectally in dosage unit formulations.
[0186] Thus, for example, the pharmaceutical compositions according
to the invention may be administered parenterally. The term
"parenterally" as used herein includes, but is not limited, to
subcutaneous injections, intravenous, intramuscular, intrastemal
injection or infusion techniques. The pharmaceutical composition
may be in the form of a sterile injectable aqueous or oleagenous
suspension. This suspension may be formulated according to known
methods using those suitable dispersing or wetting agents and
suspending agents which have been mentioned above. The sterile
injectable preparation may also be a sterile injectable solution or
suspension in a non-toxic parenterally-acceptable diluent or
solvent, for example as a solution in 1,3-butanediol. The
acceptable vehicles and solvents include but are not limited to
freshly prepared aqueous cyclodextrin solutions, particularly of
hydroxyalkyl derivatives of .beta.- or .gamma.-cyclodextrin or
carboxyalkyl derivatives of .beta.- or .gamma.-cyclodextrin or
carboxymethylethyl .beta.- or .gamma.-cyclodextrin or other
suitable derivative, as discussed in more detail below. In
addition, sterile, fixed oils are conventionally employed as a
solvent or suspending medium. For this purpose any bland fixed oil
may be employed including synthetic mono- or diglycerides. In
addition, fatty acids such as oleic acid find use in the
preparation of injectables.
[0187] Alternatively, and most desirably for human use, the
pharmaceutical compositions according to the invention may be
administered through buccal drug delivery. The term "buccal" refers
to delivery of a drug by passage of a drug through the buccal
mucosa into the bloodstream. Buccal drug delivery can be effected
by placing the buccal dosage unit between the lower gum and the
oral mucosa opposite thereto of the individual undergoing drug
therapy. Excipients or vehicles suitable for buccal drug
administration can be used, and include any such materials known in
the art, e.g., any liquid, gel, solvent, liquid diluent,
solubilizer, or the like, which is nontoxic and does not interact
with other components of the composition in a deleterious manner.
The dosage unit is fabricated so as to dissolve gradually over a
predetermined time period, to produce a substantially saturated
drug solution in the saliva of the buccal cavity, allowing
absorption of E.sub.2-CDS through the mucosa, wherein drug delivery
is provided essentially throughout the time period. The buccal
dosage unit may further comprise a lubricant to facilitate
manufacture, e.g., magnesium stearate or the like. Additional
components that may be included in the buccal dosage unit include
but are not limited to flavorings, permeation enhancers, diluents,
binders, and the like. The remainder of the buccal dosage unit
comprises the bioerodible polymeric carrier, and any excipients
that may be desired, e.g., binders, disintegrants, lubricants,
diluents, flavorings, colorings, and the like, and/or additional
active agents.
[0188] The buccal carrier can comprise a polymer having sufficient
tack to ensure that the dosage unit adheres to the buccal mucosa
for the necessary time period, i.e., the time period during which
the E.sub.2-CDS is to be delivered to the buccal mucosa.
Additionally, the polymeric carrier is gradually "bioerodible",
i.e., the polymer hydrolyzes at a predetermined rate upon contact
with moisture. Any polymeric carriers can be used that are
pharmaceutically acceptable, provide both a suitable degree of
adhesion and the desired drug release profile, and are compatible
with the E.sub.2-CDS to be administered and any other components
that may be present in the buccal dosage unit. Generally, the
polymeric carriers comprise hydrophilic (water-soluble and
water-swellable) polymers that adhere to the wet surface of the
buccal mucosa. Examples of polymeric carriers useful herein include
acrylic acid polymers and copolymers, e.g., those known as
"carbomers" for example, Carbopol.RTM.. Other suitable polymers
include, but are not limited to hydrolyzed polyvinyl alcohol,
polyethylene oxides (e.g., Sentry Polyox.RTM.), polyacrylates
(e.g., Gantrez.RTM.), vinyl polymers and copolymers,
polyvinylpyrrolidone; dextran, guar gum, pectins, starches, and
cellulosic polymers such as hydroxypropyl methylcellulose (e.g.,
Methocel.RTM.), hydroxypropyl cellulose (e.g., Klucel.RTM.),
hydroxypropyl cellulose ethers, hydroxyethyl cellulose, sodium
carboxymethyl cellulose, methyl cellulose, ethyl cellulose,
cellulose acetate phthalate, cellulose acetate butyrate, and the
like. The dosage unit need contain only the E.sub.2-CDS and the
carrier. However, it may be desirable in some cases to include one
or more additional components. For example, a lubricant may be
included to facilitate the process of manufacturing the dosage
units; lubricants may also optimize erosion rate and drug flux. If
a lubricant is present, it will represent on the order of 0.01 wt.
% to about 2 wt. %, preferably about 0.01 wt. % to 0.5 wt. %, of
the dosage unit. Suitable lubricants include, but are not limited
to, magnesium stearate, calcium stearate, stearic acid, sodium
stearylfumarate, talc, hydrogenated vegetable oils and polyethylene
glycol. In any event, the E.sub.2-CDS will most desirably be
incorporated into the buccal dosage form as a complex, preferably a
substantially saturated complex, with a hydroxyalkyl or
carboxyalkyl or carboxymethylethyl or other derivative of .beta.-
or .gamma.-cyclodextrin, as discussed in more detail
hereinbelow.
[0189] E.sub.2-CDS may also be administered in accord with this
invention in the form of a transdermal patch for transdermal
administration of the drug. The transdermal patches may include a
variety of additional excipients which are conventionally employed
to facilitate the transdermal administration of an active agent.
Examples of such excipients include but are not limited to
carriers, gelling agents, suspending agents, penetration-enhancing
agents, dispersing agents, preservatives, stabilizers, wetting
agents, emulsifying agents, and the like. Specific examples of each
of these types of excipients are well-known in the art and any
conventional excipients may be employed in the transdermal patches.
Examples of suitable permeable surface layer materials are also
well-known in the art of transdermal patch delivery, and any
conventional material which is permeable to the E.sub.2-CDS to be
administered. Specific examples of suitable materials for the
permeable surface layer include but are not limited to dense or
microporous polymer films such as those comprised of
polycarbonates, polyvinyl chlorides, polyamides, modacrylic
copolymers, polysulfones, halogenated polymers, polychloroethers,
acetal polymers, acrylic resins, and the like. Specific examples of
these types of conventional permeable membrane materials are
described in U.S. Pat. No. 3,797,494. Additionally, suitable
penetration-enhancing agents are well known in the art as well.
Examples of conventional penetration-enhancing agents include
alkanols such as ethanol, hexanol, cyclohexanol, and the like;
hydrocarbons such as hexane, cyclohexane, isopropylbenzene,
aldehydes and ketones such as cyclohexanone, acetamide,
N,N-di(lower alkyl)acetamides such as N,N-diethylacetamide,
N,N-dimethylacetamide, N-(2-hydroxyethyl)acetamide, esters such as
N,N-di-(lower alkyl)sulfoxides, essential oils such as propylene
glycol, glycerine, glycerol monolaurate, isopropyl myristate, and
ethyl oleate, salicylates, and mixtures of any of the above. Again,
as discussed in more detail hereinbelow, E.sub.2-CDS is
advantageously used in transdermal formulations as a complex,
especially a substantially saturated complex, with a hydroxyalkyl
or carboxyalkyl or carboxymethylethyl derivative of .beta.- or
.gamma.-cyclodextrin.
[0190] E.sub.2-CDS may also be administered in accord with this
invention in the form of suppositories for vaginal or rectal
administration. These compositions can be prepared by mixing
E.sub.2-CDS (advantageously as a complex, especially a saturated
complex, with hydroxypropyl-.beta.-cyclod- extrin,
hydroxyethyl-.beta.-cyclodextrin, the corresponding
hydroxyethyl-.beta.- or .gamma.-cyclodextrin derivative or the
carboxymethyl or carboxyethyl or carboxymethylethyl derivative of
.beta.- or .gamma.-cyclodextrin) with a suitable non-irritating
excipient or binder which is solid at ordinary temperatures but
liquid at the vaginal or rectal temperature and will, therefore,
melt in the vagina or rectum to release the drug. Such materials
are cocoa butter and polyethylene glycols. Traditional binders and
carriers include, for example, polyalkylene glycols or
triglycerides [e.g., PEG 1000 (96%) and PEG 4000 (4%)]. Such
suppositories may be formed from mixtures containing active
ingredients in the range of from about 0.5 wt/wt % to about 10
wt/wt %; preferably from about 1 wt/wt % to about 2 wt/wt %.
[0191] For topical/dermal use, creams, ointments, jellies,
solutions or suspensions, etc., containing E.sub.2-CDS (desirably
complexed with one of the cyclodextrin derivatives named in the
preceding paragraph) can be employed.
[0192] For intranasal use, a powder spray, suspension, gel or
ointment may be utilized, preferably a powder form of E.sub.2-CDS,
which may be complexed with one of the cyclodextrin derivatives
discussed in the preceding two paragraphs.
[0193] It will be apparent to those familiar with the patent and
non-patent literature regarding E.sub.2-CDS, that complexation with
cyclodextrin derivatives as well as formulation with such
derivatives provides particularly useful dosage forms of
E.sub.2-CDS for a variety of routes of administration. See, for
example Bodor U.S. Pat. Nos. 5,017,566; 5,002,935; 4,983,586; and
5,024,998; all of which are incorporated by reference herein in
their entireties and relied upon. See also patents describing
hydroxyalkylated derivatives of .beta.- and .gamma.-cyclodextrin
such as Pitha U.S. Pat. Nos. 4,596,795 and 4,727,064 and Muller
U.S. Pat. Nos. 4,764,604 and 4,870,060 and Muller et al. U.S. Pat.
No. 6,407,079.
[0194] Cyclodextrins of particular interest for complexation with
E.sub.2-CDS include: hydroxyalkyl, e.g. hydroxyethyl or
hydroxypropyl, derivatives of .beta.- and .gamma.-cyclodextrin;
carboxyalkyl, e.g. carboxymethyl or carboxyethyl, derivatives of
.beta.- or .gamma.-cyclodextrin; .beta.-cyclodextrin sulfobutyl
ether; carboxymethylethyl-.beta.- or .gamma.-cyclodextrin;
dimethyl-.beta.-cyclodextrin; and randomly methylated
.beta.-cyclodextrin. 2-Hydroxypropyl-.beta.-cyclodextrin
(HP.beta.CD), 2-hydroxypropyl-.gamma.-cyclodextrin (HP.gamma.CD),
randomly methylated .beta.-cyclodextrin,
dimethyl-.beta.-cyclodextrin, .beta.-cyclodextrin sulfobutyl ether,
carboxymethyl-.beta.-cyclodextrin (CM.beta.CD),
carboxymethyl-.gamma.-cyclodextrin (CM.gamma.CD) and
carboxymethylethyl-.beta.-cyclodextrin are of special interest,
especially hydroxypropyl-.beta.-cyclodextrin,
hydroxypropyl-.gamma.-cyclo- dextrin,
carboxymethyl-.beta.-cyclodextrin and carboxymethyl-.gamma.-cyclo-
dextrin. 2-Hydroxypropyl-.beta.-cyclodextrin (HP.beta.CD) and
2-hydroxypropyl-.gamma.-cyclodextrin (HP.gamma.CD) as well as
carboxymethyl-.beta.-cyclodextrin (CM.beta.CD) and
carboxymethyl-.gamma.-cyclodextrin (CM.gamma.CD), are of special
value for complexation, and incorporation of E.sub.2-CDS into
pharmaceutical formulations as a HP.beta.CD-complex or
HP.gamma.CD-complex or CM.beta.CD-complex or CM.gamma.CD-complex is
highly desirable. Moreover, for use in men or women, a buccal
dosage form, especially a buccal tablet or wafer or disk,
advantageously having a disintegration time of about 15-30 minutes,
or a buccal patch (in which the drug is released only from the side
which adheres to the buccal mucosa while the other side is
nonpermeable), has particular advantages as it can be readily
self-administered yet provides better bioavailability than oral
dosage forms because the E.sub.2-CDS passes directly into the
bloodstream from the buccal mucosa. (The cyclodextrin derivative is
not absorbed, of course.) The formulations for buccal
administration are preferably anhydrous for reasons of storage
stability. In lower animals, parenteral dosage forms are often
considered more practical and of course provide better
bioavailability. HP.beta.CD is also advantageously used in
parenteral dosage forms for E.sub.2-CDS, both as a complexing agent
and as a solvent as seen in the animal tests described hereinabove.
HP.gamma.CD, CM.beta.CD or CM.gamma.CD,
hydroxyethyl-.beta.-cyclodextrin,
hydroxyethyl-.gamma.-cyclodextrin, carboxyethyl-.beta.-cyclodextrin
or carboxyethyl-.gamma.-cyclodextrin may, for example, be used
instead.
[0195] In particularly advantageous embodiments of the invention,
buccal administration may make use of the inventions of Nagai et al
described in U.S. Pat. Nos. 4,226,848 and 4,250,163, both of which
are incorporated by reference herein in their entireties and relied
upon. Thus, a buccal mucosa-adhesive tablet may be formulated for
use herein comprising: (a) a water-swellable and mucosa-adhesive
polymeric matrix comprising about 50% to about 95% by weight of a
cellulose ether and about 50% to about 95% by weight of a homo- or
copolymer of acrylic acid or a pharmaceutically acceptable salt
thereof, and (b) dispersed therein, an appropriate quantity of
E.sub.2-CDS, typically from about 0.5 to 2.0 mg for use in women
and a lesser amount for use in men, as a substantially saturated
complex with 2-hydroxypropyl-.beta.-cyclodextrin. Ideally, for
storage stability, the tablet is anhydrous. Again, one of the
aforementioned other cyclodextrins, e.g. hydroxyalkyl or
carboxyalkyl or carboxymethylethyl .beta.- or .gamma.-cyclodextrin
derivatives, may be utilized in place of the
2-hydroxypropyl-.beta.-cyclodextrin.
[0196] While the buccal compositions according to the invention may
optionally include one or more excipients or other pharmaceutically
inert components, one of the advantages of these dosage forms when
they comprise E.sub.2-CDS as a cyclodextrin complex is that they
can be prepared with the minimal amount of excipients necessary for
shaping and producing the particular form, such as a tablet or
patch. Excipients may be chosen from those that do not interfere
with the E.sub.2-CDS, with cyclodextrin or with complex formation.
A simple solid buccal dosage form consists of the substantially
saturated E.sub.2-CDS-cyclodextrin complex compressed with a small
amount (e.g. about 1% by weight) of a suitable binder or lubricant
such as magnesium stearate. Sorbitol may be added to the complex as
well as magnesium stearate to aid in fast dissolution and to give
good mouth feel.
[0197] The buccal dosage form may be a liquid. In that case, it can
for example be obtained by dissolving a substantially saturated
complex of E.sub.2-CDS in cyclodextrin in a minimum amount of
water, for example 500 mg of the substantially saturated complex
with HP.beta.CD in 0.5 mL water (50% w/w solution), or 500 mg of
the substantially saturated .gamma.CD complex in 1.0 mL of water. A
few drops of such a solution can be inserted into the buccal cavity
and retained there for about 2 minutes to allow for absorption
through the buccal mucosa. Nevertheless, solid buccal or other
transmucosal dosage forms are generally preferred over liquid
forms.
[0198] As will be apparent to those skilled in the art to which the
invention pertains, the present invention may be embodied in forms
other than those specifically disclosed above without departing
from the spirit or essential characteristics of the invention. The
particular embodiments of the invention described above are,
therefore, to be considered as illustrative and not restrictive.
The scope of the invention is as set forth in the appended claims
rather than being limited to the foregoing description.
* * * * *